Water Intoxication (Overdose) Symptoms and Treatment

Published: November 19, 2013
Last reviewed: March 8, 2018

What is water intoxication definition?

Water intoxication or poisoning is a life-threatening condition caused by excessive water drinking that results in a drop of blood sodium levels (1). Drinking as little as 2 liters of water per hour for few successive hours can result in water intoxication.

Water intoxication does not likely occur by accident but by conscious exaggeration, such as by drinking several liters of water in few hours or more than 10 liters per day. 

Symptoms and signs of water intoxication in adults can include headache, vomiting, swelling of the hands and feet, confusion, seizures, coma or even death.

The medical term for water intoxication is dilutional hyponatremia. Synonyms include water overdose and water poisoning.

Acute and Chronic Water Intoxication

By definition, in acute water intoxication, blood sodium level drops under 130 mmol/L within 48 hours, and in chronic intoxication in more than 48 hours (18,47,52).

Symptoms and Signs

Early Symptoms

First symptoms of water intoxication can appear when the blood sodium levels fall below ~130 mmol/L and can include:

  • Headache
  • Nausea, vomiting or diarrhea
  • Restlessness, irritability
  • Lightheadedness, dizziness
  • Difficulty concentrating
  • Fatigue, muscle weakness, unstable gait
  • References: (1,16,24,45)

NOTE: Clear urine by itself is not already a symptom of water intoxication; you can excrete clear urine when you are normally hydrated or overhydrated.

Late Symptoms (Severe Water Intoxication)

The following symptoms may develop from several hours to few days after the onset of the first symptoms, when the blood sodium levels fall below ~105 mmol/L:

  • Muscle cramps, tremor, shaking
  • Swelling of the hands and feet, or abdomen (ascites), especially in alcoholics
  • Drowsiness, blurred vision
  • Confusion, unusual behavior, agitation, hallucinations, delirium
  • Coughing up blood (due to lung edema)
  • Less urination than expected from the fluid intake (38)
  • Seizures (convulsions): jerky limb movements, unusual grimacing
  • Collapse
  • Coma
  • Death, usually within 1-2 days after onset of symptoms
  • References: (1,16,24,28,38)

The faster the drop of the sodium levels, the more severe the symptoms (1).


  • Sudden increase of the body weight (up to several kilograms), but not always; for example, a person who is initially dehydrated and drinks a lot of water can still be dehydrated and thus has lower than normal body weight, but may already suffer from water intoxication (29).
  • Dilated pupils on both sides
  • Slow heart rate (bradycardia)
  • Increased frequency of breathing (in pulmonary edema) or decreased frequency and volume of breathing (in respiratory arrest)
  • Bluish discoloration of the lips and hands (cyanosis due to pulmonary edema)
  • Decreased (hypotension) or increased blood pressure (hypertension)
  • Hypothermia
  • Rigid posture with arms bent inward toward the body and hands held on the chest, clenched fists, and legs held out straight (decorticate posture)
  • References: (24,48,55,58)

Short-Term Effects on the Body Organs

  • Brain swelling (cerebral edema)
  • Lung swelling (pulmonary edema)
  • Muscle breakdown (rhabdomyolysis)

Long-Term Complications

An episode of a severe hyponatremia may leave a person with a permanent brain damage resulting in:

  • Mental retardation
  • Diabetes insipidus
  • Persistent vegetative state
  • Hearing loss
  • Cerebral palsy
  • Gait abnormality
  • References: (17,29,54,55)

Causes and Risk Factors

The cause of water intoxication is drinking excessive amounts of water or other beverages that contain little or no sodium, such as tea, coffee, fruit juices, soft drinks, beer and even sport drinks in combination with low sodium intake from foods.

Factors that increase the risk of water intoxication:

  • Female sex
  • Low body weight (infants, children, small women)
  • Low sodium intake (fasting, starvation)
  • Poorly controlled diabetes mellitus with ketoacidosis (55)
  • Certain drugs (see below)
  • Water retention due to (29):

    • Syndrome of inappropriate (excessive) secretion of the antidiuretic hormone (SIADH) in which kidneys are not able to excrete excessive fluid; causes include severe pain, stress, prolonged hard exercise (marathon), surgery, cancer or certain brain or lung disorders or drugs.
    • Heart failure, kidney failure, nephrotic syndrome (a kidney disorder with protein loss in urine), malnutrition with poor protein intake (kwashiorkor), and other causes of hypoproteinemia, liver cirrhosis, hypothyroidism, adrenal insufficiency (Addison’s disease).
    • Nephrogenic syndrome of inappropriate antidiuresis (NSIAD) — a rare genetic disease in male infants (55)
  • References: (13,43,48,55)

Mechanism (Pathophysiology)

Overhydration along with low sodium intake results in a drop of blood sodium levels (hyponatremia), which in turn results in a drop of blood osmolality. According to the principles of osmosis, water then moves from the space with lower into the space with higher osmolality, that is from the blood into the body cells, including the brain cells, which swell. Brain swelling (cerebral edema) causes the brain to get compressed within the tight skull, which is the main cause of symptoms of water intoxication and, eventually, death.

Examples of Water Intoxication (Media and Medical Case Reports)

1. Water Intoxication in Infants

Water intoxication due to diluting baby formula or treating diarrhea in sick infants with plain water is described here.

2. Child Abuse

Forced water drinking is a form of punishment of children (7).

  • In 2002 in Utah/USA, a 4-year old girl died after her parents forced her to drink about a gallon (3.8 liters) of water within few hours (32).
  • In 2002, in Florida/USA, a babysitter forced a 3-year old girl to drink 3 quarts (2.8 liters) of water in 4 hours. The girl died the next day (33).

3. Water Drinking Contests and Games

  • People have died after drinking water in amounts such as 7.5 liters in few hours in water contests (11) and fraternity hazes in colleges (10).
  • In 2012 in Sweden, a 12-year old girl died after drinking 6 liters of water within few hours of playing poker (every player had to drink a glass of water for every lost game). She died few days later (51).

4. “Water Diet” for Weight Loss

An attempt to lose weight quickly with a combination of very restricted diet and hence low sodium intake and drinking large amounts of water to suppress the appetite can result in fatal hyponatremia.

  • In 2008, in England, a 40-year old woman was on a calorie-restriction diet during which she was consuming very little salt but drinking a lot of water. One day, after about 1 week of her diet, she drank about 4 liters of water in less than 2 hours and then developed severe headache, collapsed and lost consciousness. She died in the hospital the next day (26).

5. Exercise-Associated Hyponatremia (EAH) and Encephalopathy (EAHE) in Marathon or Triathlon Runners

Runners can develop hyponatremia if they drink excessive amounts–typically more than 1.5 liter per hour–of water or other beverages, including most commercial sport drinks that contain insufficient amount of sodium (14,29).

Other causes and risk factors for exercise-associated hyponatremia (29):

  • Hard exercise lasting more than 4 hours
  • Hot weather, which means more sweating and hence more drinking
  • Athletes, especially women, with low body weight, high sweating rates and high salt losses in sweat
  • Taking non-steroidal anti-inflammatory drugs (NSAIDs), such as indomethacin or ibuprofen, which stimulate water retention and sodium loss with the urine (19). Acetaminophen is considered safe in this regard (46).

Cases of death due exercise-associated hyponatremia:

  • In the 2002 Boston marathon, a 28-year old woman died due to excessive drinking of a commercial sport drink (34).
  • In 2005, in Washington DC/USA, a 25-year old man died a day after drinking 3 gallons (11.4 liters) of water during and after a 12-mile bike ride (35).

6. Overhydration in Heat-Related Illness

  • In 1996-97, several US soldiers suffered from hyponatremia with confusion, nausea, vomiting or seizures after drinking 2 or more liters of water in an attempt to avoid heat stress (31).

7. Attempt to Hide Drug Abuse

In attempt to dilute urine samples for drug testing, some individuals drink large amounts of water on the day before testing (4,41). Such urine has low specific gravity, which can be easily identified during testing, so cheating is not likely effective.

  • In 2003, a 43-year old man drank 5 gallons (19 liters) of water along with 20 capsules of a diuretic Uva ursi or bearberry (which probably stimulates sodium excretion) over few hours before drug testing (he was recently smoking marijuana) (42). He was lethargic but had no seizures. He was treated successfully with an intravenous infusion of 3% saline.

8. Psychogenic Polydipsia or Compulsive Water Drinking

Some individuals with schizophrenia or other mental disorder can drink up to 15 liters of water per day. This is called compulsive water drinking or psychogenic polydipsia.

  • In 1980, 20 individuals with schizophrenia and psychogenic polydipsia lasting up to 28 months were evaluated for hyponatremia due to drinking 7-43 liters (!) of water per day (36). Their blood sodium levels ranged from 98 to 124 mmol/L (normal levels are 135-145 mmol/L).

9. Beer Potomania

Beer contains very little sodium, so excessive beer drinking with poor food and hence sodium intake can result in hyponatremia (37,38). Chronic alcoholics also often have protein malnutrition. Low blood sodium levels result in low osmotic pressure and low protein levels in low oncotic pressure of the blood, which results in the movement of water from the blood into the brain cells (brain edema) and in the body cavities (distended abdomen or ascites).

  • In one case from 2012, a man in his thirties, was drinking at least 10 liters (more than thirty 12-oz cans) of beer per day and eating nothing for few days. He became confused but remained conscious; during examination, his hands were shaking and his abdomen was distended. His blood sodium level was 105 mmol/L (normal = 135-145) and blood serum osmolality was 225 mOsm/kg (normal = 280-300). Urine osmolality was less than 1.005 (normal = 1.010-1.025).

10. Suicide Attempt

Some people have tried to kill themselves by drinking large amounts of water.

11. Intravenous Infusion of Hypotonic Fluids (Containing No or Little-Sodium)

An intravenous infusion of a hypotonic fluids, which contain less sodium than the blood, such as 5% dextrose in water (DW5 or D5W), can lead to hyponatremia (53). After surgery, the release of the antidiuretic hormone (ADH) is often increased, which results in water retention but normal sodium excretion; this means that an individual who receives intravenous infusion after a surgery can develop hyponatremia (19).

12. Gastric Lavage

Gastric lavage with large amounts of plain water may result in water absorption and hyponatremia (5,39).

  • As reported by Forensic Science International journal in May 1995, an 21-year old woman died after gastric lavage with 7.8 liters of water within 2 hours (40).

13. Enema

  • Enema using tap water can cause dilutional hyponatremia, especially in infants, children and elderly (49).
  • Cleansing of the colon with water before barium enema can also cause water intoxication (50).
  • A 3-year old boy developed hyponatremia after colon irrigation with plain water (56).

14. Transurethral Resection of Prostate (TURP) Syndrome

Water absorbed from irrigation during endoscopic prostate resection or, rarely, during other endoscopic procedures (cystoscopy, percutaneous nephrolithotomy, arthroscopy) can result in, sometimes fatal, hyponatremia within 15 minutes to 24 hours after the procedure (12).

15.  Syndrome of Inappropriate ADH Secretion (SIADH)

In certain disorders, the antidiuretic hormone (ADH), which prevents water loss from the body by inhibiting urination, is secreted in excessive amounts despite normal hydration, which results in water retention and hyponatremia. This is called syndrome of inappropriate ADH secretion or SIADH. Common causes of SIADH include certain brain and lung disorders, cancers and medications (chemotherapeutics, an antiepileptic drug carbamazepine) (8,25).

16. Cystic Fibrosis

Individuals with a rare genetic diseases cystic fibrosis lose excessive amounts of sodium in sweat so they are more prone to develop hyponatremia after drinking water.

17. Medications

Medications that stimulate water retention and/or sodium excretion, which can both result in hyponatremia, when taken with excessive amount of water (6,43):

  • Anticonvulsants (antiepileptics), such as sodium valproate, carbamazepine, phenytoin
  • Antidepressants (SSRIs, TCAs, monoamine oxidase inhibitors).
    • A 82-year man who was taking a tricyclic antidepressant (mirtazapine) and ACE inhibitor (ramipril), got confused several hours after drinking 3 liters of water over 4 hours in preparation for an urine-flow study (43). In the hospital, hyponatremia was diagnosed and successfully treated.
  • Antidiabetics: chlorpropamide
  • Antipsychotics, such as haloperidol
  • Barbiturates
  • Chemotherapeutics, such as vincristine
  • Cholesterol-lowering drugs, such as clofibrate (44)
  • Desmopressin spray (an analog of the hormone ADH), a drug used to treat bed wetting (enuresis) in children (6).
  • Diuretics, such as thiazides, indapamide, furosemide
  • Opioids, such as morphine
  • Other: ACE-inhibitors (lisinopril, losartan), amlodipine, proton-pump inhibitors (omeprazole), amiodarone, and the antibiotics, such as trimethoprim-sulfamethoxazole and ciprofloxacin

18. Ecstasy (MDMA) or Amphetamine Use

People who take stimulant drugs, such as ecstasy or amphetamine, can dance for several hours without rest, so they can lose a lot of water and sodium with sweat. These drugs can stimulate thirst and secretion of the antidiuretic hormone and hence water retention, which can, in combination with excessive drinking, result in hyponatremia (19).

  • Several young people have died after taking ecstasy, dancing and drinking various amount of water (up to 7 liters within 1.5 hours) afterwards (15,30).

Differential Diagnosis

CHART 1: Health conditions with similar symptoms as water intoxication (23)



Water Intoxication Headache, vomiting, increased urination, confusion, unsteady gait, agitation, seizures, coma  Swelling of the hands and feet, dry or sweaty skin, normal skin turgor, normal or increased body weight, clear urine
Severe dehydration Thirst, nausea, headache, fatigue, confusion, coma Dry skin, prolonged skin turgor, decreased body weight (>5%), decreased urination, dark urine
Heat exhaustion Thirst, headache, fatigue Pale, cool and sweaty skin, increased, increased breathing and heart rate, body T (37-40 °C)
Alcohol intoxication Unsteady gait, disorientation, vomiting, fatigue, coma Alcohol odor
Gastroenteritis Diarrhea, vomiting, abdominal cramps Signs of dehydration
Adrenal insufficiency or crisis Fatigue, weight loss, skin pigmentation, abdominal pain, salt craving
Nephrotic syndrome Fatigue Foamy urine, general body swelling (edema)
Kidney failure (acute or chronic) Anorexia, nausea, vomiting, fatigue, changes in urine volume Body swelling (edema)
Syndrome of inappropriate ADH secretion (SIADH) 59 Nausea, headache, weakness Normal blood pressure, no edema
Cerebral salt-wasting syndrome Headache, lethargy, agitation
Left heart failure with lung edema Fatigue, chest pain, weakness, difficulty breathing (dyspnea) Increased breathing rate, decreased breathing sounds during auscultation
Hypothyroidism (myxedema coma) Fatigue, feeling cold Cool, dry skin, swelling, especially in lower legs, increased body weight, decreased body temperature
Liver cirrhosis Nausea, fatigue Abdominal swelling (ascites)

Diagnosis, Lab Tests

Blood Tests:

  • Low sodium levels (<135 mmol/L)
  • Other electrolytes are usually within normal ranges
  • Low osmolality (<275 mOsm/kg)
  • Acidosis
  • Reference: 38

Urine Tests:

  • Low sodium; in SIADH: high sodium (>20 mmol/L)
  • Low osmolality (<100 mOsm/kg); in SIADH high osmolality (>1,200 mOsm/kg)
  • Low specific gravity (<1.010); in SIADH high osmolality (>1.032)
  • References: 8,20,38

Magnetic Resonance (MRI):

  • MRI can reveal brain swelling (55)

First Aid

In an individual with severe headache, vomiting or seizures, it is important to differ between dehydration and overhydration: A severely dehydrated person will always have significantly reduced body weight (>5% loss of b. w.) and, usually, prolonged skin turgor. An overhydrated person can have normal or increased body weight or, after prolonged exercise, even slightly reduced weight, and, occasionally, swollen hands and feet. What to do to an overhydrated person:

  • If agitated, try to calm him or her down.
  • Do not give him or her anything to drink or eat.
  • Call an ambulance (in the U.S.: 911).


Treatment of water intoxication with severe symptoms, such as seizures, may include water and salt restriction (in hypervolemia), salt tablets (in hypovolemia) (27), high-protein diet, intravenous fluid infusion (usually hypertonic 3% saline), diuretics (furosemide), arginine-vasopressin (AVP, ADH) antagonists (demeclocycline, conivaptan, tolvaptan) and anticonvulsants (antiepileptic drugs) (18,21,22,27,57).

Chronic hyponatremia should be treated slowly — blood sodium levels should rise slower than 0.5 mmol/L/hour, otherwise serious neurological complications, such as central pontine myelinolysis, can develop (47).


Water intoxication can be usually treated successfully without consequences.

Bad prognostic factors:

  • Blood sodium levels below 105 mmol/L (mortality up to 50%) (18)
  • Pulmonary edema (29)
  • Pneumococcal meningitis (55)
  • Hypoxia (61)
  • Women in childbearing period (61)


  • During marathon, triathlon or other endurance event, drink only to thirst, have salty snacks, avoid NSAIDs from 24 hours before to 6 hours after the race (28).
  • During few days before marathon and on the day after marathon, eat regular salty foods to build up sodium stores in your body. Do not try to overhydrate yourself before marathon (28).
  • Salt tablets during the race are not recommended because they affect blood sodium levels too quickly and may cause stomach cramps.

Frequently Asked Questions

What is the safe amount of water you can drink in a day?

A healthy adult on an average diet with usual salt consumption can drink up to about 11 liters of water in a day, if needed (9).

A healthy adult who eats nothing or very little (fasting, starving) and hence consumes no or very little salt can safely drink up to about 5 liters of water per day.

How much water is safe to drink in one hour?

The adult kidneys can excrete 0.7-1 liter of water per hour, so this is the amount that can be assumed as safe to drink in one hour. According to Current U.S. Military Fluid Replacement Guidelines, a person should not drink more than 1.4 liters of water per hour (9).

Are there any benefits of drinking excessive amounts of water?

There are no known benefits of drinking water in excess of the body needs. It is not clear if drinking large amounts of water helps prevent kidney stones in individuals with a personal or family history of kidney stones.

Is water intoxication painful?

People who consider to make a suicide usually ask this question. Severe water intoxication is usually accompanied with severe headache, nausea, vomiting, exhaustion and seizures. Severe hyponatremia caused by water overdose, or even treatment of hyponatremia can lead to permanent neurological disability.

What is the difference between hyperhydration and overhydration?

The term hyperhydration is usually used for excessive amount of water in the body and is just the opposite of dehydration. A hyperhydrated person usually has some form of body swelling (generalized edema, edema in the legs, edema in the abdominal cavity or ascites).Hyperhydration may be present with or without hyponatremia.

The term overhydration is usually used for drinking of excessive amount of water in a short time resulting in water intoxication and hyponatremia. Someone who overhydrates him/herself can become hyperhydrated, normally hydrated or remain dehydrated (if dehydrated at the start of drinking). For example, a dehydrated marathoner who quickly drinks excessive amounts of plain water after the race may still be dehydrated but already having hyponatremia due to overhydration.

77 Responses to Water Intoxication (Overdose) Symptoms and Treatment

  1. G. Lake says:

    My daughter forgot to drink water for an ultrasound of her uterus, so as fast as she could, drank a little over two litres of water. She immediately and over the next hour felt nauseous, dizzy and had a headache and blurry vision. She was urinating. She also had watery loose stools. She read about this condition online and went to the nearest emergency. There they did an EKG and took her vitals. Everything was okay. The doctor told her she had a virus (because of the watery bowel movements.) She tried to get across that she was worried about water intoxication but was not taken seriously. That was in the morning. She went back to work and all of her symptoms went away. But she is worried about the delayed symptoms. Did she drink enough water to be worried about? What should she be looking for in symptoms? Should she be eating salt? Any help you can give would soothe her worries as the hospital was clearly not much benefit.

  2. Lschnei16 says:

    I have been suffering from severe constipation I just started an enema 2 hours ago first one was normal saline solution 133 ml which produced no result after 30 min I then repeated it twice by refilling the same bottle (133 ml) with warm tap water … still no results in the BM area but I now have a headache am dizzy and feeling a tightness in my chest as well as a little wobbly on my feet is this normal? Or could it be hyper hydration?

  3. Mayra says:

    I drank a lot of water today, so much that my urine was clear with a tiny hint of yellow. I felt a little nauseous, but have had no other symptoms. I was wondering if water intoxication happens suddenly or can happen after so many hours? Its been almost 2 hours since I last drank water, and I still feel a little bit nauseous, but again don’t have any other symptoms. Do you think I would be okay at this point? Thank you!

    • Jan Modric says:

      Having clear urine is not abnormal by itself; it can occur after drinking normal amounts of water. You didn’t say how much you drank and in what period of time. Symptoms of water intoxication can develop suddenly within few hours of drinking and can continue to worsen for several hours. If the nausea is worsening and if you have headache or other symptoms, you may want to visit a doctor.

  4. Ethan Alberto says:

    Im 15 years old, and to prepare for a hydration test, i drank 3 bottles of water in a row yesterday. Today, i have a headache, im dizzy, and really worried. What should i do?

  5. Caitlin Harris says:

    I have been prescribed desmopressin and have been taking them for over a week now but now I have a bad headache and have been vomiting and been feeling sick today. Could this be the start of hyponatraemia? I have been drinking a lot aswell.

    • Jan Modric says:

      Yes it could. Please go to a doctor right away and do not drink excessive water.

      • Michelle says:

        I had to have a pelvic ultrasound this morning and did not know until getting there that my bladder had to be full…I ended up drinking about 2 to 2.5 liters of water in an hour or less maybe within 20-30 minutes…as soon as the test was over I went to the bathroom and have continued to go normally all day (urine). I also have been eating a lot of food that has salt and only have drank fluids other than water…no headache no swelling…could doing it this time for the test cause water intoxication? I have been stressing about it.

        • Jan Modric says:

          If you have no symptoms, you do not need to worry. If you are otherwise healthy (not having problems with the electrolyte levels in the blood), such amount of water, even if not recommended, should not be harmful.

          • Michelle says:

            Would it be a slow onset or would it happen quickly if you have symptoms? I am trying to not be too worried today. It’s been almost 24 hours and no real symptoms. Can I begin drinking water again. I have been too scared to drink any type of straight water.

          • Michelle says:

            I have had a few loose stools this morning but also am on my cycle. Would this be connected to the water from yesterday or is it more likely from my cycle. I normally get looser stools around this time anyways. No other symptoms.

          • Jan Modric says:

            Water alone should not cause loose stools, so, especially if you can relate them to a cycle, are not likely from water intoxication. Loose stools are not a typical symptom of water intoxication.

            Symptoms of water intoxication usually appear quite suddenly, several hours after drinking water, but not likely more than 24 hours after. You have probably already excreted all the excessive water you have drunk yesterday. In most cases, the amount of water you’ve said you have drunk (2.5 L) could cause water intoxication only if you would drink it every hour, few hours in a row.

            You can drink and eat normally, as usually. If you do not drink you may actually become dehydrated. You can know that you drink just about right amount of fluid when you urinate 3-7 times per day and your urine is clear or pale yellow and you are not thirsty.

          • Michelle says:

            This afternoon I have had some headache off and on, tiredness and did have a little chest discomfort but it has passed and my legs have had some pain (a little cramping). I did go to the park this morning and go on a walk. Would these be worrisome from the water intake from yesterday morning? I did go to an urgent care last night and they tested my urine and said that my kidneys showed to be functioning normally. Do I need to go back and be further evaluated?? Or could this maybe be signs that I was dehydrated this morning since I didn’t drink much this morning other than my coffee before going out.

          • Jan Modric says:

            Michelle, I do not know. I am not a doctor and I can’t help you with these further questions.

  6. Dylan says:

    Hi . My name is Dylan I am a 23 year old body builder . I am a vegetarian and have been for 2 years . I have started eating once a day and roughly been consuming around 1900 calories per day .i have been doing this routine for two months now . I recently decided I was going to do a salt water flush and took 2 tablespoons of sea salt with about 16 ounces of water . The flush worked and I felt completely fine other than having an urge to grab a gatoraid about an hour later . I went on a hike then out to eat I did have some salty foods for lunch but nothing more than the usual. Later that day I went to bed around 12 am . Then woke up around 5 am. I was very scared feeling and very confused. I couldn’t stand and was very shaky about 30 minutes later I was able to stand up but was very unstable. I got some water and started to feel better . So I went back to sleep when I woke up I felt a lot better but later on in the day I started to get lingering effects of that same feeling. Mind you I do drink a lot of water and I would say More than I should But I have never felt this way . Any advise on what happened

    • Jan Modric says:

      “the flush worked…” — if this means you had loose stools, then your symptoms could be from dehydration and maybe from low blood sugar (hypoglycemia).

  7. William Tierney says:

    I drank somewhere between 3-4 litres of water in 2-3 hours to help with a bladder problem I was having about 4 days ago. At the time, I was a bit dizzy and seemed a bit slower than usual, but I ate some very salty food and an electrolyte sachet. I’ve had a bit of a headache for 3 days now, but it’s not a severe one and it’s comes and goes and is mainly where my sinuses are. I don’t really have any other symptoms, but as a hypochondriac I worry about these things, and as a medical student I know just how bad this condition can be, so I was just wondering if it was water intoxication, would the symptoms be worse than they currently are after 4 days, with just a very mild headache?

    • Jan Modric says:

      When you are on regular diet that includes some salt and especially when you additionally consume some salt, drinking 3-4 liters of water in 2-3 hours (as a single event) is very unlikely to cause water intoxication. Common causes of sinus pain are teeth problems, anxiety and viral infections.

  8. James says:

    Hi I’m a 120 pound male who drank 3 quarts of water in about 1.5 hours to 2 hours. It’s been a day, and all I’ve been feeling is a little lightheaded lately and a very mild headache. I have no other symptoms besides this. Should I seek treatment or will I be fine if I just let my symptoms die down over a few days?

  9. edoardo says:

    Hi is water intoxication cumulative ? let s say if a drink a little too much every day is that too much incremented every time ?
    And what to do if i have symptoms of light water intoxications ?
    Take sodium ?

    • Jan Modric says:

      Water intoxication can be cumulative, but not likely from drinking little too much. What amounts do you have in mind? When you suspect you have water intoxication yopu should stop drinking and eating, call a doctor and not try to treat yourself with salt or anything.

  10. yusra says:

    For one week now , am in water fasting … I don’t eat any thing till after 12 hrs. .. then I drink 2ltr of water in an hour… I sleep n wake up at 4 or 2 I drink 2 or 1.5 litters …. today I feel headach n little week, little diherrea n little vomiting .. I went to the doctor I explained. . He tested my blood n my stool … he said I have only typhoid n he gave me oral rrehydration salt BP…. my question, do I drink alot of water? N seriously I don’t trust this doctor. . Can t be possible am fine ?

    • Jan Modric says:

      You only need to drink as much as needed to have colorless or pale yellow urine, which means you are well hydrated. When you are dehydrated, your urine becomes dark yellow, you become thirsty and have dry mouth. Unless you are sweating a lot, you probably do not need more than about 2 liters of water per day. Do not drink more than 1 liter per hour or more than 4-5 liters per day.

      Headache and vomiting might be symptoms of water intoxication and could develop after drinking as little as 2 liters of water in an hour.

  11. Harry says:

    I consumed too much water because of stone in my kidney. That is why I have problems such as swelling my face ,headache etc. Please tell me what I can do now for overcome this problem.

  12. K3nd4ll says:

    Hello. I have a few questions about water intoxication.
    About 3 months ago I became dehydrated. I almost fainted and since then I’ve been drinking tons of water. Lately I’ve cut back on the “tons” of water to limiting myself to drinking no more than a two or so 16 oz bottles a day, because I still felt as if I was sick. At the beginning of this journey, I went to the doctor. They checked my urine and blood and said nothing was wrong at the time. Even if I’ve decreased my drinking of water since then, is it possible to still have hyperhydration? I’m assuming no because when I was drinking A LOT of water (don’t know the exact amount) then the tests came back okay. I get headaches on a regular basis and feel nauseated as well constantly. So the question is could I still be suffering from hyperhydration? I’m wondering because during the first few days I wouldn’t stop drinking water, and I’m not dead yet. I was unaware that hyperhydration really existed at the time, and the doctors just told me to drink a lot of water. I had tremors and kept thinking I was dehydrated, when really I’m assuming at the time I was hyperhydrated. Another thing is that I am constantly thirsty nowadays, and I can’t identify why. (I don’t think I have schitzophrenia)

    • Jan Modric says:

      When you drink a lot of water and then decide to drink less, the amount of water in your body decreases within one day or so. If the tests showed no abnormality you probably did not have water intoxication even when you were drinking a lot. So, it is not likely that you have water intoxication now.

      32 oz of water per day may not be enough. An average sedentary adult living in a moderate climate may need about 65 oz of fluid per day (from all water sources–beverages and foods–combined). So, in case you do not get a lot of water from foods (fruits, vegetables) and liquids other than water (soup,milk, fruit juices), 32 oz may not be enough to keep you well hydrated.

      You may want to read a detailed explanation about:
      How much water do you need per day?
      Symptoms of dehydration

  13. Alex says:


    The article above says medications like SSRI can cause water intoxication? Why is that? Does SSRI cause too much salt to excrete or something? I was prescribed Prozac, so how much water can I drink in an hour? And how many liters of water can I safely drink in day while on Prozac? Please answer these questions. Thanks.

    • Jan Modric says:

      SSRIs can cause water retention in some people. The extent of water retention depends on the drug dose and can vary greatly from person to person, so I cannot say which amount of water per hour or day would be safe. In the article above there is a case mentioned when a man has reportedly drunk 3 liters of water in 4 hours and developed symptoms of hyponatremia.

  14. Ellen barry says:

    I was told he my doctor to drink 2 pints of water a day cause I was getting cramps in my feet now my chest is wheeze I had chest infection 22nd April and was put on steroids and antibiotic Andy cough bottle could it be my chest not cleared up or is it from too much water

    • Jan Modric says:

      2 pints (one liter?) of water per day or per hour? 2 pints of water per day is often not even enough and 2 pints per hour is way more than you need and it could actually cause water intoxication if repeated several days in a row while eating very little.

      Wheezing is not really typical for water intoxication, so it’s more likely from the lung infection. You may want to visit a doctor.

  15. Deborah Baker says:

    I am a borderline diabetic and I just got a steroid shot yesterday so my sugar so shut up really high to bring them down I drank 4 bottles of water that I bought at Walmart just a regular size and I drank that within two and a half to three hours so to bring my blood sugar down so I could go home

    • Jan Modric says:

      Drinking water does not lower blood sugar levels and this amount in such a short time can be dangerous.

  16. David says:

    I been keeping track of my water intake and read that the kidneys can excrete up to 1 liter of water an hour. What about foods that naturally or contains water in them? Does it increase your risk of water intoxication if you already drank 1 liter in a hour? For example, lets say someone drinks 1 liter of water every hour and eats a lot of food that contains water through out the day. Like for breakfast they drink 1 liter of water, then have cereal with 8oz of milk and eat a fruit like an orange. Then for lunch they drink 1 liter of water, eat 12oz of chicken noodle soup that mainly has water, with a small salad and an apple…etc So if someone is always drinking 1 liter of water every hour and also consumes many foods that contains water will that add to their water intake where it could cause water intoxication? Or is it that as long as sodium is consistently in their diet from foods the added water in foods won’t cause water intoxication? Please let me know because I am very curious about this. Thanks!

    • Jan Modric says:

      Every water in every form (water, juice, milk, cooked cereals, fruits…) counts as water. Why would someone want to drink 1 liter of water every hour? This has no benefit and yes, it can be dangerous, even if it’s only 1 liter. Every water intake beyond 10 liters per day is potentially dangerous. Drinking 1 or 2 liters of water in a single hour (and not in the following hours) by itself should not be dangerous for health adults.

  17. Shawn says:

    I suffer from anxiety and OCD and terrified of water intoxication. I was rinsing my mouth with water after brushing my teeth and I felt terrified that I might swallow some water from rinsing. To ease my fear I probably rinsed 50-100 times to prove to myself that I couldn’t swallow the water unless I purposely swallowed the water which I am confident that I didn’t swallow any after each rinse. But, lets just say if I did ended up swallowing a lot of water from rinsing so much and developed water intoxication my question is how long does symptoms of water intoxication appear after swallowing so much water? It has been 12 hours now since I rinse my mouth and I do not have a headache, nor vomiting or any symptoms of water intoxication. I do feel a little dizzy, heart is racing and nervous but that is because of my anxiety making me think I could still develop water intoxication from rinsing my mouth so much. Please let me know so I can stop panicking. Thank you

    • Jan Modric says:

      OK; I’m late for this, so if you do not have any symptoms now, you probably do not have water intoxication. Water intoxication does not likely occur by an accident. like swallowing some water during mouth rinsing.

  18. Anonymous says:

    I’m a young adult, male, underweight. Four days ago I drank four liters of water in about two-and-a-half hours. Besides feeling a bit sleepier than usual, nothing adverse happened, and it stayed this way for three days. I began drinking less water than usual and eating more salt than usual, as well. Just yesterday, I started feeling nauseous. It hasn’t worsened, but it’s stayed persistent today. This seems unlike a typical case of water intoxication, but I just want to be sure. I’ve also been sneezing lately, so the nausea could be related to some other sickness instead.

    • Jan Modric says:

      Sneezing and nausea may be from a viral infection or possibly, from an allergy. If you are otherwise healthy and you were eating regularly recently, four liters of water in 2.5 hours should not be dangerous, especially if you were dehydrated at the time of drinking. No need to consume excessive salt.

  19. Kirsty says:

    This happened to me 7 months ago I was getting an ultrasound and was told to keep drinking lots of water I ended up drinking about 3 litres in an hour and started throwing up in the hall and then when I went home I started getting all the above symptoms ended up in hospital overnight they thought I was having a stroke and I’m only 25 but they found out it was hyponatremia got treatment and was fine.now 7 months later I’m starting to get partial seizures that are getting worse I’m waiting for an EEG and MRI but I’m just wondering do you think this is the cause. Ive had no head injury and no other problems like this until last year

  20. Robin Glinskas says:

    My boyfriend may have water poisoning. What can I do to help him?

  21. Kanupriya says:

    I suffer from anxiety (hypochondriac). I’m obese (34 yo, female, 209 lbs) having joint pain. Two days ago I made a decision to start drinking 3 L of water per day. I’m drinking a glass of water (250ml) every hour from the time I wake up till the time to sleep. I’m not diabetic or hypertensive. My eGFR is 129.
    Since this morning, I’m feeling anxious if I’m drinking more than necessary, if my sodium levels are ok etc. Please tell me if this is just anxiety or something is wrong.

    • Jan Modric says:

      Kanupriya, 250 mL water per hour or 3 liters per day is not dangerous for a healthy person and should not decrease sodium levels.

  22. Anynomous says:

    I was fasting and I drank about 3 liters in 10 minutes. I felt very dizzy and I couldn’t think properly anymore and after a few hours my whole body was swollen. My muscles started to hurt and I barely could look through my eyes because they were so thick. I didn’t look like myself anymore at all. I got headaches and I had very low consciousness, I can’t even remember everything properly anymore and didn’t know what I was doing anymore. I have a low body weight and I am a young female. After several hours I ate a lot of salt and also food to try to get some electrolytes. I got diarrhea and still have it after a few days. I’m worried that I now have brain damage, is the chance for this big? And don’t tell me to go to a doctor because I can’t do that, I just want to know. And is there any way to find out if I have any damage without going to a doctor?

    • Jan Modric says:

      From your description (swelling, dizziness, muscle pain, headache) it’s quite possible you actually have experienced water intoxication. Diarrhea was probably from consuming excessive salt – if this was the only cause it should resolve soon. If you are still fasting, I strongly suggest you to go back to normal diet with normally salted foods. Do not try to treat anything with excessive salt or other electrolytes, except from what you normally consume with foods. Drink appropriate amount of water – not too much and not too little.

      I don’t know if you have brain damage. There are people who had water intoxication without any consequences. A neurologist can evaluate this by performing a neurological examination. If you or some you know knows any doctor personally, try to arrange a visit. You could suspect you have a brain damage if some symptoms, like dizziness would persist.

  23. Karina says:

    My 3 yr old just drank 600mls in one hour! Is this bad ? What can happen.. was complaining of sore tummy screaming for a doctor! ! Should i be worried hes calm now asleep in bed

  24. AKHIL says:

    I drank 20 litres of water in 20 hours, 1 litre after every 1 hour. Did it cause permanent brain damage and mental retardation. Have i become mentally retarded ? How do i know that i have suffered mental retardation and brain damage? Can you please tell me the tests to check for mental retardation and brain damage?

    • Jan Modric says:

      Akhil, drinking 20 liters of water in 20 hours by itself is not necessary harmful, especially when you drink only one liter per hour. When excessive water drinking causes severe headache and vomiting, seizures and loss of consciousness, you may expect to have brain damage. If you are worried, visit your doctor.

  25. abee says:

    Hi , my son is 10 years old and he is a cp kid with slow development due to meningitis when he was few weeks old. As a mother I mean giving him 6 oz, 180 ml of water right after he gets up in the morning and again in the afternoon after lunch next night after dinner. He has epilepsy. Is it recommend this much of water for him ? Please advice. Tq.

    • Jan Modric says:

      Abee, if your son is 10 years old, I see no reason why 6 oz of water would be bad for him. If you meant 10 months, then he should not get any additional water besides breastfeeding or formula.

  26. Kimwanna says:

    When i workout I can drink about 120-150 oz of water. though i do a lot of work 5 days a week. the other 2 I do drink about 90 oz so i wont be all cramped up wont be dehydrated when I get back in the gym and running. I’ve been doing this for about 7 years.

  27. Monsurah Sadiq says:

    A healthy man who drink 2 litres of water a day, suddenly starts drinking 3 litres or more a day (due to excessive taste) and also urinate frequently. What could be the cause of this sudden excessive taste? the person is not diabetic.

  28. Lisa says:

    I drank a liter of water in about 5 minutes today and felt very fizzy about half an hour later. When I arrived at my destination I was still dizzy and had trouble focusing. It was a bit better When I returned home. I ate some salty food. I’ve had s headache all day. It’s better now, but I can still feel a bit of discomfort. I don’t unusually drink that much water in such a short time. Guess this was water intoxification? Should I keep eating salty food?

    • Jan Modric says:

      Lisa, to my knowledge, it’s quite unusual to get water intoxication or even get dizzy from just 1 liter of water. If you repeatedly experience this, please visit a doctor, because you might have an underlying problem, for example, hyponatremia. Mild water intoxication is a transient disorder that corrects after drinking less water and consuming some salt, but you do not need to continuously eat more salt or avoid water. Again, please go to the doctor.

  29. ivy says:

    hie,some people usually recommend u drink at least 500ml within a minute or less if you are feeling a headache.I want know if this a good recommendation or not and why?
    also a friend of mine suggested that if i want good acne free ,smooth and flawless skin i shud drink 1.5 litters tap water in 3mins, 500 ml mid day another 500ml afternoon around 4 or 5pm.wont this cause water intoxication.am still hesitating on starting this.

    • Jan Modric says:

      ivy, I’m not aware of any effect of water drinking on headache relief. The idea of drinking 1.5 liters of water in 3 minutes sound very sill to me. I don’t know why would this help. 500 mL or 1.5 liters of water in few minutes should not cause water intoxication in a healthy adult, but it does not make any sense for purposes you mentioned.

      If you have acne you can try eliminating certain foods from your diet – there is no exact list of foods to eliminate known, but you can just use your intuition. If you think you eat a lot more foods than you think you should, try to reduce it and see if it helps.

  30. Elmarie says:

    Would drinking a sports drink (that contain some sodium?) when excessive water intake is suspected but typical symptoms not seen and blood work not done to affirm hypoNa, helpful?

    • Jan Modric says:


      a typical sport drink may not contain enough sodium to prevent water intoxication (with hyponatremia) when you drink excessive amount of it.

  31. JSingh says:

    Very good and informative article on the topic.

  32. Mark Holt says:

    I just drank 3 litres of water in under 4 minutes. I am very worried that I will become very ill due to the amount of water consumed. I weigh about 200 lbs, and have been working out doors for the last 2 weeks straight.
    What do you suspect will happen?


    • Jan Modric says:

      I don’t know what will happen – at the time I’m writing this, you have probably already excreted all excessive water with the urine.. While drinking 3 liters of water at once is a lot, it may still cause no danger if you did not drink a lot of water before or after that and you have consumed some usually salted food in the last 48 hours…When you are thirsty , which usually means you are dehydrated, drinking a lot is far less dangerous than when you you are already well hydrated.

  33. Emm says:

    Hello, for a teen girl,how much water is recommended per hr and what do you do if you drank too much and have headaches? I drink about seven glasses in five hrs is that bad?

    • Jan Modric says:

      Unless you have a certain disease and your doctor said you should limit the amount of water, seven glasses, if one glass is about 1 cup (240 mL), that is about 1,6 liters, in five hours is not bad. Do not drink more than 1 liter of water per hour, though.

      A healthy teen girl, in average, may need about 2 liters of water per day (from beverages and foods combined), but if you sweat a lot, you may need more. If you drink too little, you may lose weight; for example, if you notice you’ve suddenly lost 1 kilogram of body weight, this is most likely from dehydration, so you need to drink 1 liter of water to regain your normal weight. If you drink too much, you will urinate more frequently. It is very unlikely to suffer from water intoxication from the amounts of water you’ve mentioned, but headache can have many causes, and drinking water might worsen it. If you often have headaches, please visit a doctor.

  34. andro says:

    I am daily drinking lots of water. Per hour min 1litre and per day I am drinking maximum 8 to 10 litres.
    But I am feeling little bit stress and headache. But still I am drinking. I am drinking water like this from my childhood. But in sometime, when I drinking 2 litres of water continuously I feeling my head is so weight. Is this is any problem. ? And I am eating very well and urin count also increased. But I feel healthy? Am I in any dangerous situation? if yes means what I need to do now?
    Thank u dear.

    • Jan Modric says:

      Hi, andro

      drinking 8-10 liters of water would be needed only if you were losing that much by sweating, vomiting or diarrhea. You need to drink only as much water as you lose. I can’t tell you how much you would need but unless you are very physically active or you live in a hot environment, you probably do not need that much. Most moderately active people in temperate environment probably need up to 3 liters of water per day. By drinking 8-10 liters per day you are in danger to develop low blood sodium levels (hyponatremia), especially if you drink a lot in a short time, like 2 liters in one hour.

  35. Michael Elliott says:

    Hi, About 6 years ago I mistakenly drank a mouthful of Turpentine thinking it was water, to combat the effect I drank about 2 litres of water within 30 minutes I now know that this is not recommended.
    I almost instantly started getting a headache and sort medical advise. I have had back and neck X-rays a ct scan and everything has come back normal, six years on I still have a constant pressure in my brain and get frequent headaches. In your opinion can my symptoms be a result of what happened six years ago or just a coincidence.
    If it is a result of water intoxication is there anything I can do.
    The doctors are saying it’s not linked and probably a migraine.
    Thank you for taking the time to read this.

    • Jan Modric says:

      It is extremely unlikely your symptoms, both 6 years ago and now, are due to water intoxication. 2 liters of water in 30 minutes in an adult is really not an amount that could cause any problem.

      • Sophie says:

        Before surgery the doctor suggested that I get hydrated I drank 10 big glasses
        of water the day before and woke up with my entire body shaking uncontrollably, I realized it was mineral, and salt, electrolytes imbalance, and I took a mineral supplement and a little bit of sea salt water. Also was on diflucan and I think that can cause shaking, anxiety and hallucinations it was sooooo scary to have this going on . I drank this to make me feel better and this stopped the shaking.

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