Did you know an overdose of water can also be fatal. It leads to dilution of the blood and causes hyponatremia - a disease which causes nausea, fatigue, vomiting and even mental disorientation! Also too much water means undue pressure on the kidneys. When the kidneys can't flush out the excess water, the blood becomes waterlogged and the water enters our cells which swell up like balloons. Scary, isn't it? So as a rule of thumb drink 8 to 10 glasses of water everyday. Don't overdo it!