Most of the normal urine is light yellow liquid, the main component is water, accounting for 96% ~ 97% of urine, and the other components are urea, uric acid, creatinine and other nitrogenous substances. The urine output excreted by normal people per day and night is 1000~2000ml, and the average daily urine output is about 1500ml.
The bladder is located in the pelvis and is an organ for storing urine, and its capacity is 300~500ml. In men, the bottom of the bladder is connected to the rectum, and in women, the back wall of the bladder is connected to the uterine bladder space. When the bladder is empty, its inner mucosal surface presents many folds, and the inner wall is smooth when filled.
Traditional Chinese medicine believes that the bladder is the place where water gathers, and in the surface of the kidney, it has the function of dissolving qi and water. There is a limit to the capacity of the bladder to hold urine. The so-called holding urine is that the urine contained in the bladder exceeds the capacity of the bladder itself, but consciously endures not to excrete.
Generally people have had the experience of holding urine, and holding urine for a long time is not good for health, and can also lead to urinary system diseases. As the saying goes, "flowing water does not rot". Normal urination not only excretes metabolites in the body, but also has a self-cleaning effect on the urinary system and urinary tract.
So what are the problems caused by holding urine?
I can't pee if I want to
When the bladder accumulates 200ml of urine, the human body will begin to urinate, at this time if there is no urination, the bladder can also retain urine, but continue to accumulate to 500~600ml (women will be more), the bladder will appear excessive expansion, and the muscles that control urination expand, long-term do not urinate in time, the bladder will be overloaded, severe cases will lead to urinary retention and can not urinate independently.
Diseases of the urinary system
When a large amount of urine is stored in the bladder, the precipitate is concentrated, resulting in an increase in the saturation of calcium salts in the urine and an increase in the probability of formation of urinary tract stones. When holding urine, the bladder volume is enlarged, vascular compression, mucosal ischemia, leading to reduced resistance. At this time, bacteria will take advantage of the deficiency (medically called urinary tract retrograde infection), grow and multiply, and easily cause urinary diseases such as urethritis and cystitis.
It should be noted that after women once hold urine (such as driving for a long time and unable to urinate in time), urinary tract infections are more likely to occur, and the probability of occurrence is several times higher than that of men, which is related to the physiological structure of female urethra. There is a clinical experience that women will have at least one urinary tract infection in their lives, which means that women are very likely to get urinary tract infections.
Kidney disease
There is a good physiological anatomical mechanism of "anti-reflux" of urine draining from the ureter into the bladder, which is sneaked "tunneled" into the bladder wall. However, when holding urine, the pressure in the bladder continues to increase, even greater than the pressure at the ureteral opening, which will lead to urine "reflux". Holding urine can even induce pyelonephritis.
Urinary retention can increase pressure in the bladder and reflux of urine along the ureter, resulting in hydronephrosis, followed by renal parenchymal compression, ischemia, and even necrosis. This is called reflux nephropathy.
Sudden onset of cardiovascular disease
Holding urine can also cause physical and psychological tension, and the continuous increase of bladder capacity causes increased intra-abdominal pressure and increases blood pressure in hypertensive patients; Patients with coronary heart disease develop arrhythmias and even angina. Therefore, holding urine is more likely to induce serious consequences such as sudden cardiac death for most elderly patients with underlying diseases such as hypertension, coronary heart disease, and diabetes.
If the elderly suddenly urinate after holding urine for a long time, due to the rapid emptying of the bladder, the pressure in the abdominal cavity drops, and the amount of blood returning to the heart slows down, it will make the vagus nerve excited, the cerebral blood supply is insufficient, blood pressure is reduced, the heart rate is slowed, and even voiding syncope occurs. Rapid urination after holding urine, and gross hematuria will also occur.
Bladder rupture
There is a "entertainment" that is popular in the summer during dinner with friends, called "beer skewers". Friends drink the same amount of beer at the same time and compete to see who can get the most toilet at night. This game is actually very dangerous. In the state of holding urine, the incidence of bladder rupture is high in the face of impact and accidents.
There are also urines that have to be held
But some people will ask: "Many times when doing urological or gynecological ultrasound in the outpatient clinic, doctors still ask patients to hold urine, why?" "Doctors ask patients to hold urine in order to make ultrasound and diagnosis by doctors easier. In some patients, after holding urine, the sonographer will have a diagnosis of "bilateral pelvis separation". This is what we just called the reflux phenomenon after holding urine.
Rest assured, this symptom will disappear after timely urination. For an occasional urine holding test, it will not cause serious harm to the body.
Finally, I would like to remind everyone that high-quality urine requires sufficient drinking water to produce. Normal adults drink about 1500ml of water a day, which we commonly call "8 glasses of water". If there is a large amount of exercise that day, sweat will be produced, and we can appropriately increase the amount of water we drink. Drink water must not be drunk when you feel thirsty, and you should drink water on time instead of drinking water on demand.
Well, having said that, I'm going to go get a glass of water now. I hope everyone can drink more water and not hold urine.
Author: Shanghai Pudong New Area Zhoupu Hospital
Chief Physician of Urology Yang Bo
Review: Expert of the National Health Science Popularization Expert Database
Fudan University Cancer Hospital
Professor of Urology and Chief Physician Ye Dingwei
Curator: Wu Weihong, Tan Jia
Editor: Luan Zhaolin