Which is worse: wanting to urinate as soon as you drink water or drinking a lot of water but not being able to urinate?

Tuchong Creative

Have you ever had this experience: you feel like peeing as soon as you drink water? However, I have also heard of people who rarely need to go to the toilet no matter how much water they drink. Which of these two situations is better?

In fact, these two things are very important and are also what everyone must do in daily life. The reason for doubt is mainly because of the worry about physical problems. If you want to know the answer, you must first understand a process, that is, how the water you drink turns into urine.

It is certain that water does not turn into urine immediately after drinking it. It needs to go around in the body for a long time. Let's briefly describe it. After drinking water, the first places to feel the moisture are the mouth and throat. However, the real absorption of water starts from the stomach, and most of the water is actually absorbed in the small intestine mucosa.

Where does the absorbed water go? The answer is that it enters the blood and becomes part of the plasma, and then circulates throughout the body. When the body senses that new water has entered, it will excrete part of the water originally in the blood. When this part of water flows through the kidneys, it will first form primary urine under the action of the glomerulus, which is the initial state of urine. Then, it will be repeatedly reabsorbed by the renal tubules and finally form urine, which flows into the bladder along the ureter for storage. When you go to the bathroom, the urine is discharged when you imagine the mountains and flowing water in your mind. The whole process ends here. It usually takes 40 minutes from drinking water to urine formation.

So, since the water we drink will eventually be excreted as urine, why should we drink water?

Because drinking water is essential to maintaining good health. 70% of our body weight is water, especially more than 90% of plasma is water. The existence of so much water is necessary. First of all, it can play a role similar to water transport in plasma. For example, it transports nutrients to cells and takes away metabolic waste. Secondly, it can play a role in maintaining osmotic pressure. Junior high school biology teaches that if the osmotic pressure inside and outside the cell is different, the normal morphology of the cell will be destroyed. In addition, water is the basis of metabolism. All biochemical reactions in cells, such as the tricarboxylic acid cycle, gluconeogenesis, and glycolysis, must be completed in a water environment. Therefore, it is not wrong to say that water is the source of life.

The body excretes waste water in the form of urine every day, and also secretes digestive juices, saliva, tears, and sweat when the ambient temperature is high or when exercising. These are all water. Since there is loss, it must be replenished quickly, otherwise once the water in the body is reduced, dehydration will occur. It can be said that people can go without food for a day, but they cannot go without water. Severe water shortage can be fatal.

Why does urine have different shades of color? What's the reason? And what does the amount of urine have to do with it?

Normal urine is slightly yellow because it contains bilirubin metabolites. Normal urine is light yellow. If you don't drink enough water, the urine will be concentrated and the color will turn yellow or even dark yellow. On the contrary, if you drink too much water, the color will be lighter. If you have certain diseases, such as nephritis, urinary tract infection, or eat too much food containing pigments, such as carrots and pumpkins, the color of urine will be darker. As for the amount of urine, it is related to the amount of water you drink. For healthy people, the more water you drink, the more urine you will naturally produce. If you drink very little water, you may even have less urine.

Why do some people feel like going to the toilet after drinking water, while others don’t? Is this normal?

Most of the cases are normal. As long as you drink enough water, you will naturally urinate more. And the faster you drink water, the faster urine is formed. Especially if you eat some diuretic foods, such as watermelon and beer, urine will be formed even faster. However, drinking water is not equal to urination, because there is a urine storage tank in our body, which is the bladder. Under normal circumstances, when the urine in the bladder reaches about 300 ml, you will feel the urge to urinate. At this time, the brain will receive a signal from the bladder saying that the bladder is full and it will "overflow" if you don't pour it out. The brain will prompt you to find a place to "drain water" to relieve the pressure on the bladder. However, if you don't find a suitable place, the bladder and urethral sphincter will remain tense and resist to the end.

However, everyone's physique is different. Even if they drink the same amount of water, some people urinate more and some people urinate less. This is because people of different genders and weights have different circulating blood volumes, so the amount of water that needs to be added to the plasma is naturally different, and the excess water will be excreted.

Under what circumstances will there be increased urination? Without considering the disease, if you eat fruits with high sugar content such as watermelon, or drink beverages containing diuretic ingredients such as honey, alcohol, caffeine, etc., the urine volume will increase; when the ambient temperature is relatively low, it will stimulate the body's antidiuretic hormone secretion to decrease, and the urine volume will also increase. If you are emotionally tense, or pregnant women in the middle and late stages of pregnancy, they will also have frequent urination. In addition, increased urination may also occur in certain disease states, such as diabetes, diabetes insipidus, hyperthyroidism, urinary tract infection, or the use of diuretics and certain antibiotics will also promote urine excretion.

Under what circumstances will decreased urination occur?

If the ambient temperature is high or when exercising, the body will sweat, and the urine volume will decrease. If the body has urinary tract obstruction, renal dysfunction, and certain nervous system diseases, it will also lead to reduced urination. However, this situation is often accompanied by symptoms of water metabolism disorders, such as systemic or local edema. In addition, when antidiuretic drugs are used, urination may also decrease.

In addition, some people have very elastic bladders and stronger tolerance, and can even drink beer without going to the toilet. This does not mean that they have less urine, but that it is stored in the bladder. However, this is not a good habit, and it is very detrimental to the health of the circulation and urinary system. If things go wrong, you may suffer from urinary tract infection or nephritis. Some people have slightly poor tolerance and want to go to the toilet as soon as they feel the urge to urinate. For some people, it is purely a habit problem. For example, the act of drinking water gives the brain a signal to release water.

How much water should we drink for our health, and how do we know when we need to drink water?

According to the recommendations of the Chinese Dietary Guidelines, adult men with low physical activity levels in a mild climate should drink at least 1,700 ml of water a day, and women should drink 1,500 ml of water. If the weather is hot or if you have done a lot of physical activity, you should drink more water. The correct way to drink water is not to wait until you are thirsty due to dehydration, but to drink 100-200 ml of water every 1-2 hours. Remember to drink water after exercise or when you wake up. When you are thirsty or urinate less, it means that your body is already dehydrated. If you get used to drinking water at this time, it will affect your body over time.

Finally, to sum up, generally speaking, urinating as soon as you drink water or not urinating even if you drink more water is neither "good" nor "bad", both are normal reactions of the body. However, if you often "urinate as soon as you drink water" or "not urinate even if you drink more water", it may be pathological urination, which is of course not good for both.

This article is a work supported by the Science Popularization China Creation Cultivation Program. Author: Zhang Yu, PhD in Nutrition

Reviewer: Zhang Na, Associate Researcher, Doctoral Supervisor, Peking University School of Public Health

Produced by: China Association for Science and Technology Department of Science Popularization

Producer: China Science and Technology Press Co., Ltd., Beijing Zhongke Xinghe Culture Media Co., Ltd.