1. Help digestion: The food eaten in the mouth is digested and absorbed through the digestive process from esophagus to gastrointestinal tract after being chewed by teeth and wetted by saliva. All these links need water to accelerate the dissolution of nutrients by body fluids.
2. Waste excretion: the residual waste after digestion and absorption of food nutrition should be excreted through sweating, breathing and excretion. These different ways of excretion need the help of water.
3. Lubrication of joints: Human joints need lubricating fluid to avoid damaging the friction between bones, and water is the main source of joint lubricating fluid.
4. Balance the body temperature: When the ambient temperature is lower than the body temperature, in order to maintain the body temperature and ensure normal physiological activities, the water in the body will remain in the body due to the reduced evaporation of the narrowed pores; When the ambient temperature is higher than the body temperature, water will be discharged from the body through the expanded capillary breathing hole, which will lower the body temperature. The body ensures its survival function through the dispersion of water.
5. Maintain cells: water can promote cell metabolism and maintain the normal shape of cells; Keep skin moist and elastic.
6. Balance blood: Water can improve the circulation of blood and tissue fluid and help balance the viscosity and pH of blood.
The demand for water is mainly affected by age, environmental temperature, physical activity and other factors. The amount of urine excreted by human body in one day is about 1500ml, and the water lost from feces, breathing and skin is about 2,500ml. Therefore, the daily water demand of healthy adults is about 2,500ml, of which drinking water accounts for about 50%, water contained in food accounts for about 40%, and water produced by metabolism in the body accounts for 10. Adults living in mild climate and less physical activity should drink at least 1200ml every day. Under the condition of high temperature or strong physical labor, it should be increased appropriately. Drink plenty of water when you are sick, especially when you have a fever, because every time your body temperature rises 1, your metabolism will accelerate by about 7%.
Harm of insufficient drinking water
When water is scarce, besides feeling thirsty, there will be dry skin, cleft lip, fatigue, less urine, dizziness, headache and other phenomena, and in severe cases, there will be mental symptoms such as fever and irritability. Lack of water will lead to the disorder of gastrointestinal digestion, blood nutrition and body fluid concentration regulation, and lead to other diseases, such as backache, deformed knee joint disease and arthritis.
The harm of drinking too much water
Excessive drinking water will lead to excessive salt loss in the human body. At first, there will be dizziness, weakness, rapid heartbeat and other symptoms. In severe cases, there will even be convulsions, confusion and coma, that is, water poisoning. However, excessive water or water poisoning in the body is rare in normal people, and it is generally more common in people with abnormal liver, kidney and heart functions.
How to judge water shortage
If you don't know whether to drink more or less water, here is a little trick, which can be judged according to the color of urine. Generally speaking, human urine is light yellow. If the color is too light, maybe they drink too much water. If the color is too dark, it means that more water is needed.