Dehydration Diagnosis and Treatment in Adults

By , August 28th 2013. Last reviewed 9th March 2018.

Dehydration means a loss of water from the body. Treatment of mild and moderate dehydration in adults includes drinking plain water or other beverages.

Severe dehydration is a life-threatening condition, which requires treatment with an oral rehydration solution (ORS) or intravenous fluid infusion. A separate article describes treatment of dehydration in infants and small children.

How can you know how dehydrated are you?

Your physical symptoms can tell you how dehydrated you are [1].

Chart 1. Dehydration Stages

Weight loss 1-3% 4-6% >6%
Urination Slightly
Little or
no urine
Urine color Strong yellow Amber Dark
Skin recoil after
pinch and release
(skin turgor test)*
Up to 2 seconds Delayed
(2-10 seconds)
(>10 seconds)
Mouth and lips Dry mouth Chapped lips Chapped lips

Chart 1. *Skin turgor refers to the ability of the skin to flatten after being pinched and released.  Normally, when you pinch the skin at the back of the hand and release it, the skin should recoil immediately; any delay in skin recoil suggests dehydration.

First Aid In Dehydration

How to help an adolescent or adult person who looks acutely dehydrated:

A person who is mildly to moderately dehydrated (up to 6% loss of body weight, skin turgor <10 seconds) should get plain water, tea or similar drink without alcohol or caffeine and with no or little sugar (Chart 2), but not more than 1 liter per hour. The goal of the treatment is to regain the original body weight and excrete clear (colorless) urine again.

In hot ambient, if possible, a person should lie down in a cool place with legs raised to prevent fainting.

A person who looks severely dehydrated (>6% loss of body weight, profound fatigue) or cannot drink due to nausea or injury or has impaired consciousness should be treated by a doctor, preferably in a hospital.

Chart 2. What to drink to relieve mild or moderate dehydration?

Water, herbal tea, decaffeinated coffee Any safe and clean water is fine: tap water, bottled water, including mineral and carbonated water, clean streams or lakes
Sport drinks There is nothing wrong with sport drinks as such, but they are not needed in mild or moderate dehydration. They are a bit salty, so they can stimulate drinking.
Fruit juices, soft drinks (soda, cola), iced tea Large amounts of fruit juice contains a lot of sugar that can slow down the movement of the water from the stomach to the intestine and thus inhibit its absorption. Large amounts of sugar may also trigger diarrhea.
Green or black tea, coffee, energy drinks Large amounts of caffeine can cause anxiety or caffeine intoxication. Caffeine can transitionally stimulate urine excretion, but not significantly and is about as much effective in relieving dehydration as plain water [2,5].
Milk Milk in large amounts may trigger diarrhea, especially in lactose intolerant people. Skim milk goes through the stomach faster than whole milk, so it can provide quicker rehydration.
Clear soups Salt from a large amount of soup may trigger diarrhea.
Beer, cider or other weak alcoholic beverages (up to 4-5 vol% alcohol) A large amount of beer can cause alcohol intoxication. Alcohol can transitionally stimulate urine excretion, but beer is not dehydrating [2,3], so, when no other beverage is available, drinking beer can relieve mild or moderate dehydration.
Apple juice, pear juice, mango juice, and beverages with HFCS Beverages that contain high amounts of “net fructose” (the amount of fructose greater than glucose) may trigger diarrhea and thus worsen dehydration, especially in individuals with fructose malabsorption. The amount of net fructose in 1 liter of beverage:

  • Pear juice: 58 g
  • Apple juice: 31 g
  • Cola, sweetened with HFCS: 17 g
Water contaminated with microbes or toxins Contaminated water can trigger diarrhea and thus worsen dehydration.
Strong alcoholic drinks (wine, liqueurs, spirits) Drinking strong alcoholic beverages will more likely make you severely drunk than rehydrated.
Seawater After each liter of seawater you drink, you will likely excrete about 1.5 liters of urine, so you will have 0.5 liters of water less in your body than before drinking [15].


How much should you drink to relieve dehydration?

To properly rehydrate yourself, you may need to drink 1.5 x the amount of fluid you have lost. For example, after losing 3 kilograms of body weight due to dehydration, you need to drink about 4.5 liters of water [5,6]; the additional 1.5 liter of water is to replace the water lost in urine during rehydration. Doctors usually recommend replacing one half of lost fluid in the first 4 hours and the other half in the next 8 hours [17].

What is dehydration recovery time?

After appropriate treatment, the recovery time in dehydration can be:

  • In mild dehydration: within several hours
  • In moderate dehydration: 1-2 days [5]
  • In severe dehydration (treated by an intravenous infusion): 12-24 hours

You can consider to be completely rehydrated when you reach your usual body weight and your urine becomes clear or straw yellow.

Diet During Dehydration Recovery: What to Eat

When you are recovering from dehydration, you can have your usual meals. It can help if you limit your diet to bland foods, but you do not need to stick with once recommended BRAT diet (bananas, rice, applesauce, toast). You may want to avoid foods that can trigger constipation (low-fiber foods such as chocolate, French fries, meats, cheese, white bread) or diarrhea (fruit juices, milk, sauces, spices, etc.).

What should you do if you are severely dehydrated?

If you have symptoms of severe dehydration (>6% loss of body weight, only minimal urination) but you can walk around, try to get an oral rehydration solution from a drug store or a sport drink that contains sodium [5]. Sodium helps to retain water in your body.

When you experience any complications of dehydration, such as impaired consciousness, muscle cramps, fever or seizures, visit or call a doctor as soon as possible, because you may need an intravenous fluid infusion.

Blood and Urine Tests in Dehydration

A doctor may order blood and urine tests to evaluate the extent of dehydration and to find the underlying cause.

Blood tests can include osmolality, electrolytes (sodium, potassium), blood urea nitrogen, creatinine, glucose and ketones.

Urine tests can include 24-hour urine volume (decreased), specific gravity (usually increased) and ketones (increased in diabetes mellitus)

By the tests a doctor can determine the type of dehydration and its severity.

Management of SEVERE Dehydration

Intravenous Fluid Infusion (“I.V.”)

In severe dehydration, you may need an infusion of the fluid in a vein in one or both arms or in the neck 7. The type, amount and rate of the infusion depend on the type and severity of dehydration:

  • Isotonic solutions, such as 0.9% solution of sodium chloride [saline] also called physiological solution, or lactated Ringer solution, are the most common solutions used for the treatment of isotonic, hypertonic or hypotonic dehydration 7.
  • Hypertonic solution, usually 3% saline, can be used in some cases of hypotonic dehydration 7,11.
  • Hypotonic solution, such as 0.45% saline (with or without 5% glucose), or 2.5% or 5% dextrose solution, can be used in some cases of hypertonic dehydration (diabetic ketoacidosis with hyperglycemia) 11,16