Most ultrasound examinations do not require special preparation except for wearing loose clothing, but in order to obtain better examination results, patients are advised to pay attention to the following precautions: 1. Heart ultrasound examination should be performed by taking off shoes and lying flat on the examination bed after a moment’s rest, exposing the external chest surface of the heart, applying ultrasound coupling agent and examining through the probe; 2. Digestive system ultrasound examinations are easily disturbed by gas from the digestive tract, so examination of deep organs requires fasting or strict intestinal preparation; liver, biliary and pancreatic examination requires fasting of milk, soy products, sugar and other easily fermented gas-producing foods before the examination; light food is eaten 1 night before the examination, and fasting and fasting are required on the same day. If patients undergo intestinal and biliary X-ray imaging and gastroscopy at the same time, ultrasound examination should be performed before X-ray imaging or gastroscopy, or 3 days after the above examination; 3, gynecological examination: examination of pelvic organs, such as the uterus and its adnexa, bladder, etc., the bladder urine needs to be retained before the examination, you can drink about 1000ml of water 2 hours before the examination, 2-4 hours before the examination to avoid Urination; 4, eye examination: the examined eye needs to be closed during the examination, the non-examined eye looks flatly at the ceiling, the jaw is slightly upturned so that the pupil is located in the center, and avoid rubbing the eye during the examination to avoid the inflow of oily liquid for examination and damage to the eye.