1. People need water for all kinds of physiological activities. For example, water can dissolve various nutrients, and fat and protein can only be absorbed if they are suspended in water. Water flows endlessly between blood vessels and cells, transporting oxygen and nutrients to tissues and cells, and then discharging metabolic wastes from the body. In short, people's various metabolic and physiological activities are inseparable from water.

2. Water has a certain effect on body temperature regulation. When people breathe and sweat, they will excrete some water. For example, in the hot season, the ambient temperature is often higher than the body temperature, so people rely on sweating to evaporate some heat to lower their body temperature and avoid heatstroke. In cold weather, because of the great potential of water to store heat, the body temperature will not fluctuate obviously because of the low external temperature. Water is still the lubricant in the body. It can moisturize the skin. When the skin is short of water, it will become dry, lose elasticity and look old. Some joint capsule fluid and serosa fluid in the body can prevent organs from being damaged by friction and can rotate flexibly. Tears and saliva are also lubricants for corresponding organs.

Water is the cheapest and most powerful magic medicine in the world. The health care and disease prevention functions of mineral water and electrolyte water are well known. Mainly because water contains ingredients beneficial to human body. When you have a cold or fever, drinking more boiled water can help you sweat, reduce fever and dilute toxins produced by bacteria in your blood. At the same time, the increase of urine is beneficial to accelerate the discharge of toxins.