You have probably heard that it is important to drink plenty of water -- approximately eight to 10 glasses per day -- to maintain good health. Water is one of the basic necessities of life, making up approximately 60 percent of the human body. It may surprise you, then, to learn that it is possible to drink too much water, diluting your system and leading to a dangerous condition called hyponatremia.
Water's Role in the Body
Water, when ingested in the proper amount, helps to break down vitamins and nutrients so that your cells can use them effectively. In addition, it removes waste products and toxins, cushions joints and tissues and plays a role in the regulation of body temperature. But too much water can stress the major organs and throw the body’s electrolytes, such as sodium and potassium, out of balance. This condition is referred to as water intoxication.
Water Intoxication and Hyponatremia
Water intoxication and hyponatremia go hand-in-hand; in fact, the terms are sometimes used synonymously. Water intoxication occurs when the body has taken in a large amount of water in a short time, without excreting it. The heart and kidneys must work extra hard to try to manage the excess water in circulation, and lung tissues may fill with water. Water intoxication soon results in an imbalance between the amount of fluid and the amount of sodium in the bloodstream, a situation known as hyponatremia. An individual is considered to have hyponatremia when serum sodium levels drop lower than 135 milliEquivalents (mEq) per liter of blood; by comparison, a normal range is 136 to 142 mEq.
Symptoms of the early stages of water intoxication include nausea, vomiting, disorientation and confusion. As sodium levels drop and the condition progresses, the individual may have muscle cramps, become tired and experience seizures. He may have trouble breathing, due to the fluid in his lungs. To compensate for the extra fluid, the blood cells will try to absorb some of the water, causing them to swell, sometimes to the point of bursting. When this swelling occurs in the brain, the result can be coma and death.
Treatment involves stopping the person from ingesting any more water, and hospitalization so that sodium can be given through an IV drip. The outcome depends on how quickly the person is able to seek medical care.
General Hydration Guidelines
Water intoxication is not common and cannot result from drinking an appropriate amount of water to replenish your body’s lost fluids. Water intoxication is most likely in infants who are given too much water to drink, and in marathon runners who push their physical limits and may consume too much water. It is important to consult your doctor to find out how much water you should be drinking, based on such individual factors as your age and general health. Healthy adults who are drinking enough water, are rarely thirsty and produce urine that is clear or light-colored rather than dark yellow are probably getting the right amount of hydration.