Daily water consumption is not always better
Some people wonder, since water has many benefits, is it better to drink more of it? The answer is no. Research indicates that for a healthy adult, the daily water requirement is generally around 2500 milliliters.
While the body takes in water, it also excretes a certain amount through urine, feces, respiration, and sweating. For a healthy adult, the daily intake and output of water are roughly equal. If they are not equal, an increase or decrease in either will alter the body's internal environment. The kidneys then regulate their function by producing more or less urine.
If you drink too much water for a long period, it will inevitably lead to the kidneys being overworked, which in turn affects heart function. People often experience symptoms like fatigue, dizziness, memory loss, lack of concentration, loss of appetite, and high blood pressure. In severe cases, symptoms such as edema, increased blood pressure, shortness of breath, and palpitations may occur, making it difficult to lie flat. Some individuals might even experience severe conditions like disorientation, aphasia, drowsiness, or coma. This condition is particularly common in infants who are over-hydrated for extended periods.
Some people, feeling extremely thirsty in the summer or after exercise or physical labor, gulp down a large amount of water at once, feeling very "refreshed" and "quenched" at the time. However, they don't realize this can be harmful to the body. After physical exertion, exercise, or exposure to extreme heat, the body loses a lot of sweat. This not only depletes water but also a significant amount of salt. The more you sweat, the more water and salt your body loses. It is calculated that there are 1.5 to 3 grams of salt in every liter of sweat, which is why sweat tastes salty. If you sweat 5 liters in half a day of work, you will lose 7.5 to 15 grams of salt. If you drink a large amount of plain water at once without replenishing salt, the water is absorbed by the gastrointestinal tract and then excreted through sweat, causing further loss of salt. As a result, the salt concentration in the blood becomes too low, its ability to absorb water is reduced, and some water is quickly absorbed into the tissue cells, causing cell edema. This leads to "water intoxication," characterized by dizziness, blurred vision, and thirst. In severe cases, a person may suddenly collapse. This phenomenon is medically known as "hyponatremia."
The thirst one feels after heavy sweating is not entirely due to a lack of water in the body, but rather a feeling caused by reduced and thickened saliva, and a dry mouth and throat. The correct way to drink water in this situation is: first, rinse your mouth to moisten it and your throat, then drink a small amount of water. After a short pause, drink some more. By drinking in several small installments, you can avoid damaging your health from "water intoxication." Of course, it is even better to promptly replenish with some light salt water after sweating from labor or exercise.
Therefore, one should drink water in moderation and avoid developing the habit of excessive long-term water consumption.