Is drinking TOO much water bad for you?

Yes, drinking too much water is bad for you and, yes, it could potentially kill you too. There is such a thing as water intoxication or water poisoning and it occurs when one has too much water, usually within a short span of time. I know one doesn't normally associate water as being one of the causative factors for death. But, as they say, excess of anything can be bad, and in the case of water, excess can potentially kill. Generally, in day-to-day life we don't normally consume too much water. We generally only have as much as we require, as indicated by the feeling of thirst.  When our thirst is quenched, we are satiated and no longer keep drinking.  So, in the normal course, water intoxication is rare.  In fact, many health experts advocate drinking adequate amounts of water for its health benefits.  For certain ailments too, drinking adequate amounts of water is essential - ailments such as kidney stones. Adequately hydrating oneself can prevent formation of kidney stones, which is one of the most painful medical conditions around.  However, you do need to be careful about drinking excessive amounts of water. 

Watch out for water-drinking contests and the like. In such contests, one can go overboard and binge on water, potentially causing a health risk to the individual concerned. People in such situations are forcing themselves to have more water than their body requires and thereby overloading their body with water. More critically, these individuals are drinking large volumes of water within an awfully short period of time. The body cannot cope with the excess volume infusion and the tissues can swell up with the excess water retained by the body. This can in turn damage the cells of the body and cause electroyte imbalance - mostly in the form of dilution of sodium - one of the essential electrolytes in the body. Medically, this condition is called hyponatremia. i.e. the body contains an abnormally low concentration of sodium circulating in the blood.

The harmful effects of this fluid overload can be reversed if prompt treatment is given by infusing salt solutions and restricting any fluid intake. It is important to stress though that water intoxication is pretty rare and, as mentioned above, occurs only in certain odd situations like water-drinking contests or sometimes during marathons, where athletes tend to take in excess fluids. In the normal course, a person normally drinks only as much water as he/she requires. So, one doesn't have to get paranoid about drinking water. You just have to make sure that you don't overdo it. Drinking 8-10 glasses of water is considered normal and that should do you no harm at all.