Dehydration Complications

Published: March 8, 2018
Comments Off on Dehydration Complications
Last reviewed: December 31, 2022

Dehydration Dangers and Complications

Occasional mild to moderate dehydration rarely causes any dangers in otherwise healthy individuals. On the other hand, chronic or severe dehydration can result in life-threatening complications, especially in elderly and those with underlying chronic diseases.

1. Heat Injury

Heat injury refers to an increase in body temperature due to dehydration (with the inability to sweat and thus lose heat) and exposure to heat. Other symptoms include weakness, nausea, headache and painful cramps [14,16].

The 2 severe phases of heat injury are heat exhaustion and heat stroke.

Heat Exhaustion

Heat Stroke

Skin Sweaty, cool, pale [14] Dry, hot, flushed [4,14]
Body temperature 98.6-104 °F (37-40 °C) >106-115 °F (41-46 °C)

First aid in heat injury [14,17]:

  1. Move a person to a cool place, remove excessive clothes and enable a cool shower or bath.
  2. Offer a cool beverage, preferably plain water.
  3. Call a doctor, because a person may need an intravenous fluid infusion.

2. Heart and Circulation Complications

Dehydration can cause orthostatic hypotension — a drop in the systolic (upper) blood pressure for at least 20 mm Hg upon raising [13]. The main symptoms are dizziness or fainting within 3 minutes after raising [13]. You can prevent orthostatic hypotension in the morning by drinking 300-500 mL water 15 minutes before getting up [12].

In susceptible individuals, long-term dehydration increases the risk of blood clots in the veins (deep vein thrombosis) [11,12].

Severe dehydration may lead to a drop in blood volume (hypovolemia) and consequently inadequate blood perfusion of the tissues (hypovolemic shock). Symptoms and signs include anxiety, lethargy, clammy and pale skin, weak pulse and low blood pressure. If not treated promptly, hypovolemic shock can be deadly.

In an otherwise healthy person, even severe dehydration rarely results in heart attack. In individuals with coronary artery disease or impaired heart valves, dehydration can trigger chest pain (angina pectoris) or irregular heart rhythm (arrhythmia). When dehydration is so severe that it leads to hypovolemic shock, it may result in heart attack [5].

3. Kidney Complications

In dehydration, mucous membranes in the tubular organs, such as ureters, urinary bladder and urethra, dry up, which may increase the risk of urinary tract infections [18].

Severe dehydration can result in acute kidney failure — an inability to excrete water and waste materials through the kidneys. Marathon runners with muscle disintegration (rhabdomyolysis) may be at increased risk [8,9].

Chronic dehydration increases the risk of kidney stones [12].

4. Hypernatremia

Severe dehydration can result in elevated blood sodium levels (>145 mmol/L) or hypernatremia.

Hypernatremia can result in the movement of water from the brain cells and thus in brain shrinkage. Symptoms include confusion and seizures [10].

5. Other Complications

Dehydration can increase the risk of:

  • Acute mountain sickness [3]
  • Exercise-induced asthma [12]
  • Hyperglycemia (in diabetes mellitus) [12]
  • Yeast infection in the mouth (oral thrush, candidiasis) [7]
  • Bed sores [6]

There is a lack of evidence about the association of dehydration with fibromyalgia.

6. Dehydration and Death

An otherwise healthy person who has lost more than 10% of body weight due to dehydration can go into a coma or die. Here you can read how long you can survive without water.

  • References

      1. Helman RS, Heat stroke  Emedicine
      2. Dehydration and Rehydration Defense Technical Information Center
      3. Cumbo TA et al, 2002, Acute mountain sickness, dehydration, and bicarbonate clearance: preliminary field data from the Nepal Himalaya  PubMed
      4. Helman RS, Heat stroke, clinical presentation  Emedicine
      5. Amaro JA, Dehydration and heart attack
      6. Pressure ulcers causes  NHS Choices
      7. Malkin B, 2009, The importance of patients’ oral health and nurses’ role in assessing and maintaining it  NursingTimes
      8. Muscal E, Rhabdomyolysis  Emedicine
      9. Kidney failure  Mayoclinic
      10. Lukitch I, Hyponatremia, clinical presentation  Emedicine
      11. Kelly J et al, 2004, Dehydration and venous thromboembolism after acute stroke  PubMed
      12. Popkin BM et al, 2010, Water, hydration and health PubMed Central
      13. Lanier JB et al, 2011, Evaluation and Management of Orthostatic Hypotension  American Family Physician
      14. Heat cramps exhaustion and stroke in children  Boston Children Hospital
      15. Heat exhaustion Mayoclinic
      16. Heat illness risk factors  FPNotebook
      17. Heat exhaustion treatment  Mayoclinic
      18. Beetz R , 2003, Mild dehydration: a risk factor of urinary tract infection? PubMed