Lacunae exist on studies related to water metabolism, especially in India. This review article presents a condensed version of various research findings in water metabolism in health and disease. Lack of adequate intake of water will lead to serious health hazards and dehydration will be the first observation. Water involvements in the functioning of various cells have been the highlights of many publications. Among the many important functions of water, it serves as an excellent solvent for ions, nerves signalling, enzyme activities, mineralisation of organic compounds, disposal of waste products, hydrogen binding of proteins and hydrophobic reactions. In every organ, water and sodium metabolism are closely interlinked. Impaired water metabolisms are closely linked in many chronic diseases, especially in elderly persons. The recommended average daily intake of water is 2 – 3 litres per day. People doing exercise need to consume extra water to compensate water loss through sweats. Both dehydration and hypo hydration will lead to serious health problems. The other symptoms associated with poor water intake are cognitive disorders, dry mouth, fatigue, thirst, decreased urine output, and decreased mental and physical performance, headache and dizziness. More studies are required to set standard guidelines for water consumption for the benefits of continuous health maintenance.