Water intoxication

General

Water intoxication is a term used when too much water enters the body and dilutes the sodium in the body.  The body’s cells do not function normally in these occasions.  This is asymptomatic in early stages, but can be fatal in severe cases if untreated.  

Water is balanced in the body by a very sophisticated control system which is facilitated by the brain and the kidneys.  Healthy individuals can survive on as little as 250 ml of water or as much as 15 L.  Water is lost from the body by sweating, breathing, and urination.  Small amounts are lost in feces.  When fluid is lost from the body, electrolytes are also lost, in conditions such as diarrhea or heat exhaustion.  When lost water is replaced by plain water without electrolytes, solutes get diluted, and it leads to water intoxication.  

When too much water enters the body, cells and tissues swell up, and can burst.  The swelling of cells can affect the heart- leading to irregular heart beats, lungs- leading to pulmonary edema, brain- leading to irritability, seizures, and coma, and death. 

Causes

-         drinking too much water

-         anti-depressants

-         congestive heart failure

-         cirrhosis

-         renal failure

Symptoms 

-         nausea

-         headache

-         bloating

-         slurred speech

-         weakness/tiredness

-         muscle cramps

-         hallucination

-         seizures

-         coma

-         respiratory arrest- secondary to brain swelling 

Symptoms in babies

 Water intoxication in babies can occur because of over dilution of formula and excessive free water by mouth.  Symptoms include:

-         facial swelling or puffiness

-         irritability or drowsiness

-         drop in body temperature

-         in small children:  fatigue, headache and confusion

Diagnosis

-         History

-         Physical examination

-         Laboratory tests:  measure of sodium, potassium, urine osmolality

-         Chest x-ray

-         Electrocardiogram 

Treatment

At home, restrict intake of water and salty foods. Diuretics can be given via mouth as well.  Most patients require hospitalization.  

Prevention 

Do not over hydrate.  Specific attention should be paid when preparing baby’s formula.  Water requirement is 8 glasses a day, and should be followed accordingly.