Why do you need to hold urine during bladder ultrasound?

The bladder in our human body is where urine is stored. However, there are many diseases in life that can cause damage to the bladder, leading to abnormal bladder function and symptoms such as frequent urination and urgency, which seriously interfere with people's normal life. When you go to the hospital to check your bladder, of course you will have an ultrasound. But what many patients don’t understand is why they need to hold their urine for a bladder ultrasound examination? Let’s talk about this in detail below.

Because in the physiological structure of the human body, the uterus and its appendages are located in the center of the small pelvis, between the bladder and the rectum.

It is in an anteriorly bent and flexed position, and the ultrasound echoes of solid, liquid and gas-containing tissues are different. When the bladder is full, there is a dark area of ​​fluid on the sonogram. The uterus is a solid organ with a cavity. On the sonogram, the normal uterus is located behind the dark area of ​​the bladder, and the uterine wall is a solid dark area.

During ultrasound examination, when the ultrasonic beam enters the body and encounters gas, it will form total reflection, that is, echo zone, and no image will be displayed on the screen. Ultrasound examination uses the echo-free area to form a sound-transmitting window, and then makes a diagnosis based on the different strengths of ultrasound reflection from different tissues in the body. Therefore, if an ultrasound examination is performed when the bladder is not full, the gas in the bladder and the gas in the uterus will overlap, causing misdiagnosis or missed diagnosis. Therefore, ultrasound examinations often require patients to fast and hold their urine. This is a prerequisite for a successful examination and is very important.

Before doing a B-ultrasound, be sure to empty your bowels and bladder in the morning. Drink about 1000 ml of water before the examination and wait for about 1 hour. The examination can be carried out only when the patient has a very obvious urge to urinate. For emergency patients or those who cannot hold their urine, 500 ml of sterile saline can be injected into the bladder through a urinary catheter.

So will this kind of holding urine cause harm to the body? You should know that holding urine will cause the internal pressure in the bladder to increase rapidly, and normal urination will be affected. Moreover, holding urine frequently can easily cause diseases such as cystitis. However, holding urine during an ultrasound examination is accidental and short-term, so holding urine at this time will not cause any harm to the body.