Dear Doctor, Is there a limit to how much water I should take in a day? Are there any effects of taking too little or too much? Shamim Dear Shamim, Water is essential for the body. Almost 60-70% of the body is made up of water. It is vital for various metabolic functions of the body, maintaining salt and electrolyte balance and kidney function. Water also aids in digestion and clearing the bowels. It is responsible for keeping the protective coverings of the body moist. Generally it is said that one should take 2-3 litres (8 to 10 glasses) of water everyday. But this is not hard and fast. The amount varies as per the environmental temperature, type and quantity of food consumed, level of physical activity of the person and his overall health. Apart from this, other drinks and food substances also contain water. One may need more water in special situations like doing strenuous work, travelling in hot weather, diarrhea and or vomiting and nursing mothers. One can judge the need for water by looking at the colour of urine. Dark coloured urine, scanty urine, passing urine only once or twice in 24 hours indicates need to drink more water. Whereas less water is not good, excess can also be harmful. Excess water can cause loss of salt from body manifesting as muscle cramps and weakness. It can also put load on heart and kidneys. Hence if one has muscular cramps, feels unexplained weakness, or develops puffiness over face, breathlessness(any one or more of these) and other things being normal, he can review his water intake and reduce it. Dr Rachna Pande is a specialist in internal medicine at Ruhengeri Hospital