Some abdominal ultrasound examinations require holding urine, but it is not necessary to hold it to a certain degree. The purpose of holding urine is to fill the bladder. When doing abdominal ultrasound examinations, such as bilateral kidney, bilateral ureter, bladder uterus and uterine adnexa, a full bladder can make the urinary tract as well as the uterus and uterine adnexa appear more clearly. However, there are some abdominal examinations that do not require holding urine, such as liver and gallbladder examinations and spleen examinations, which not only do not require holding urine, but also require a fasting state in order to perform the examination.