Dehydration and Over-Hydration
Dehydration is a very serious condition. Fifteen to twenty percent of lost body weight, as water is fatal. Dehydration of as little as a two percent loss of body weight can result in impaired physiological and performance responses. Symptoms of mild dehydration include headache and fatigue. A common cause of dehydration is illness, specifically if vomiting and/or diarrhea are involved. Also very hot dry conditions and overexertion are other common causes. A good strategy when feeling poorly is to try hydrating as a first response.
It is possible to drink too much water. In fact, people have died for this very reason. Over-hydration is disruptive to nerve cell function and can produce symptoms of lightheadedness or mild vertigo. Over-hydration causes an imbalance. Too much water and not enough electrolytes, especially sodium is the result. This dilution of the body’s fluids causes dysfunction of many functions that depend on electrical activity through the electrolytes. Because brain cells are susceptible to fluid imbalances, over-hydration and water intoxication can produce neurological symptoms such as altered personality, and disoriented behavior. Water intoxication can also result in convulsions, circulatory shock, coma, and death.
Immediate medical attention may be required when symptoms of over-hydration or dehydration occur. Avoiding complications requires fluid intake (which is usually restricted and very slowly re-administered over many hours) to be very carefully monitored by a healthcare professional.