You’ve probably done it yourself at least once. However, that old stunt of holding your breath underwater just to see how long you can do so, could actually be more dangerous than you think. In 2011, two men in the city of New York held their breath underwater, and drowned.
In fact, that kind of situation is not very unusual, and according to health officials, such accidents are not restricted to children either. According to the Centers for Disease Control and Prevention, there were at least 16 cases in which people engaged in a breath-holding exercise under water in a pool, and of these, four people drowned. The deaths involved people between the ages 17 and 22, and in all the cases, the men were excellent swimmers.
Hyperventilation, or the act of stopping your breath before you go underwater is at the crux of the danger here. According to experts, when you hold your breath like this, the carbon dioxide in your body is expelled from the body, and that in turn inhibits brain signals that would have otherwise urged you to breathe. In a situation like this, you might believe that you are capable of holding your breath for much longer than you're capable of doing. When trouble strikes, a person may not even be prepared for it. The person may suddenly blackout, and the blackout is caused by the sudden fall in oxygen pressure in arterial blood.
This summer, if you are out at a pool with friends, prevent friends from engaging in such behavior. In most cases, these drownings, are very silent and deadly, and there may be no splashing about or other signs as the person blacks out and sinks to the floor.