Drinking a moderate amount of water in the morning on an empty stomach can replenish the body’s need for water while reducing blood viscosity, excessive drinking water for breakfast can easily lead to nutrient loss, aggravate the burden on the kidneys and so on. Getting up in the morning on an empty stomach and drink a cup of water, can supplement the body needs of water while reducing blood viscosity, because of hidden sweating and urine secretion during sleep, the loss of a lot of water, get up without thirst, but the body will still be due to a lack of water and blood viscosity, drinking water can reduce blood viscosity, increase circulating blood volume, is conducive to good health. If long-term excessive drinking water will have increased urination, can lead to the body of sodium, potassium, magnesium, calcium and other elements will be lost with the urine, thus causing harm to the body. If there is renal insufficiency, it may cause water intoxication and so on due to water not discharged in time.