Ultrasound attention to wear loose clothing, fasting, empty bladder, hold urine, etc., do ultrasound precautions are based on the ultrasound examination of different parts of the decision, in the ultrasound before you need to do some of the following preparations. 1. Cardiac ultrasound: when doing cardiac ultrasound, in order to facilitate the operation of the doctor, the patient needs to wear loose clothing, undressing before the examination is convenient and fast. 2. Fasting: In the ultrasound examination of liver, gallbladder, spleen and pancreas, it is necessary to fast for 4-6 hours before the examination to keep the digestive tract free of food interference and ensure the accuracy of the examination results. 3. Empty the bladder: women need to empty the urine in the bladder during the vaginal ultrasound, to avoid changes in the shape of the uterus due to bladder compression during the examination, and also not conducive to the observation of both sides of the adnexa. 4. Urine holding: ultrasound of both kidneys and bladder, female gynecological abdominal ultrasound, etc., need to be carried out in a state of full bladder, through the full bladder, can clearly observe the situation in the pelvis. On the specific precautions before doing ultrasound is not clear, it is recommended to consult a doctor.