The human body consumes a large amount of water during sleep, so drinking water upon waking in the morning is a good habit. Drinking water in the morning not only replenishes the water lost by the body's metabolism but also helps to cleanse the digestive system, stimulate the "normal function" of internal organs, and is beneficial for the body's detoxification.
Drinking water in the morning also allows water to be quickly absorbed by the intestinal mucosa into the bloodstream, thereby increasing blood volume, diluting the blood, effectively reducing blood viscosity, and promoting blood circulation. This is very beneficial for preventing coronary heart disease and cardiovascular and cerebrovascular diseases, so drinking water in the morning is a good health practice for middle-aged and elderly people. In addition, drinking water in the morning can moisten the intestines and soften stools, which is also very effective in preventing constipation.
Salt water has a disinfecting and bactericidal effect, so some people prefer to drink light salt water in the morning, believing it is more beneficial to their health. While drinking light salt water to replenish fluids after sweating in the summer is indeed healthy, it is not necessarily beneficial to drink light salt water in the morning. On the contrary, this practice is not only useless but can also be harmful to your health.
During sleep, the body's metabolism (such as physiological activities like sweating and urination) and blood circulation continue, and these activities consume a large amount of water in the body. When you wake up in the morning, the blood is already in a concentrated state (blood viscosity is high). Drinking a certain amount of plain water upon waking can quickly dilute the blood. However, if you drink salt water upon waking, it will instead worsen dehydration and make you feel thirstier. At the same time, the morning is the first peak period for elevated blood pressure. Drinking salt water at this time will cause blood pressure to rise even higher and increase the burden on the heart. Therefore, it is not advisable to drink light salt water upon waking in the morning, and it is strictly forbidden for patients with hypertension.