Why do children wet the bed? If they still wet the bed frequently after the age of 5, you should pay attention!

Bedwetting refers to involuntary urine leakage during sleep at night at least once a month after the age of 5, and lasting for more than 3 months. This may be one of the problems for many children and parents. Especially for children, finding that many of their peers have stopped wetting the bed, but they are still wetting the bed, puts them under considerable psychological pressure.

Why do children wet the bed? Is there any way to improve it? I guess many people want to find out these questions. Today we will talk about this in detail.

01 Why does bedwetting occur?

Let's go back to the basic process of urination. Our kidneys collect metabolic wastes such as uric acid, urea, and excess fluid filtered from the blood through metabolism, gather them to the renal pelvis through the renal tubule system, and then transport them to the bladder, where our urine is stored. The bladder will make a judgment based on the volume of urine. When it reaches a certain amount, the urination reflex is activated, and the sphincter contraction is controlled to open the urethra to discharge the urine from the body.

If we simplify this process, we will find that the basic rules of urination are: urine volume and bladder capacity are the two key factors.

If the urine volume is too much or the bladder capacity is too small, then this urination threshold is easily reached, and then urination is needed. However, at night, this problem is complicated, because during sleep, our overall nervous system will be relatively dull, so that we can fall asleep better to rest our bodies, and the nervous system responsible for urination is also dull to a certain extent. If we wake up, we will choose to urinate in the bathroom. However, if you are asleep and do not wake up at this time, bedwetting will occur.

Therefore, we can draw a basic conclusion: bedwetting is mainly caused by the imbalance between the amount of urine produced during sleep and the bladder capacity. If you cannot wake up in time, it will lead to bedwetting.

Therefore, the causes of bedwetting can be viewed from these two aspects.

02 Why does urine volume increase?

On the one hand, the human body has an overall balance for water. If we take in too much water, the body will choose to excrete this water, so the urine volume increases. It should be pointed out that the water intake here is not just drinking water, our food also contains a lot of water, which is a point that many people will ignore. For example, some fruits with high water content can easily increase our water intake.

On the other hand, some people may not consume a lot of water but still produce too much urine. The reason behind this lies in the body's regulation of water, typically the secretion of antidiuretic hormone.

Antidiuretic hormone is a hormone that promotes water absorption and reduces urine. It can enhance the kidney's absorption of water, thereby concentrating urine and reducing urine volume. Studies have found that many bedwetting cases are caused by insufficient secretion of antidiuretic hormone at night, which causes the body to produce a large amount of urine [1].

03 Bladder capacity issues

The bladder is the place where urine is stored. Of course, urine is not excreted immediately. Instead, it must reach a certain volume to trigger the urination reflex.

Therefore, the capacity of the bladder determines that the urination thresholds of different people are different, or in layman's terms, the amount of urine that can be accommodated is also different.

There are many factors that affect bladder volume. The first is age. Bladder volume will continue to increase with age. Younger children have smaller bladders due to development, so they naturally hold less urine.

At the same time, at the same age, the bladder volume of different people will show certain differences. This may be related to many factors such as physiology and genetics. If the bladder volume is relatively small, bedwetting is more likely to occur.

In fact, bedwetting is very common for children, especially those under 5 years old. However, if bedwetting still occurs frequently after the age of 5, then other factors may need to be considered, that is, a special type of "bedwetting" - nocturnal enuresis. Due to limited space, we will continue to discuss nocturnal enuresis tomorrow.

[1] Wen Jianguo, Zhang Weiping, et al. Chinese expert consensus on the diagnosis and treatment of enuresis in children[J]. Chinese Medical Journal, 2019, 99(21): 1615-1620.