We’ve all heard the advice, “Drink lots of water.” Water is essential to survival; in fact, human beings are composed to up to 65% water, However, it is possible to take too much water in too short a span of time. When this happens, the sudden intake of water causes a critical imbalance in the body’s level of sodium compounds and potassium. This situation is called hyponatremia, which causes the cells in the central nervous system (such as the brain) to swell.
Hyponatremia is a situation of water poisoning. While water is safe to drink, too much of it can cause the body to break down. When the cells swell, the cell membranes are put under so much strain that these may start to die.
Water poisoning is a severe condition. Symptoms may start with lightheadedness and headaches, as well as nausea and outright vomiting. As the situation worsens, the brain may malfunction so severely that the person becomes unresponsibe to stimuli. Eventually the sodium levels reach such critical levels that seizures and even a coma will ensue.
So how much water is too much? The “danger zone” varies from person to person. Factors include overall health and amount of physical activity, as well as the weather or temperature.
Some people may think that it’s okay to drink a lot of water while losing a lot of water to sweat. However, even under the most rigorous exercise, it’s dangerous to overdo water intake. That’s because the body may not be able to replace the electrolytes that quickly, so a risk of imbalance is still there. That’s why professional athletes resist the urge to gulp down large amounts of water during practice and especially during a competition. They will take controlled sips or simply wet the mouth. Others take in special sports drinks that have electrolytes.