Patients suspected of having coronary artery disease will need a coronary angiogram to confirm the diagnosis. Prior to this, you will need to undergo ultrasound, ECG, X-ray, three routine tests, infectious disease screening, biochemistry, coagulation and other routine tests before you can have a coronary angiogram, which will take about 1-2 days. After all the routine examinations meet the requirements, the nurse will prepare you for the procedure, such as skin preparation, antibacterial skin test, and bed training for bowel movement. If your condition is stable, you can go back to the ward directly after the crowning procedure. At this time, you need to pay attention to the fact that you need to drink a lot of water after the procedure because the doctor injected the contrast agent during the procedure. After the procedure, the limb on which you received the puncture should be restrained for 24 hours and the wound should not be exposed to water for three days. If your condition is more severe, you will need to be observed in the CCU for one day. In patients with coronary artery disease after bypass surgery, because large blood vessels were taken in the leg during the operation, the lateral limb circulation in the leg is not yet abundant for three months after the operation, and the calf may be swollen. What you should pay attention to at this time is that you should put on elastic stockings when you get out of bed and take them off when you return to bed to rest; you should elevate the affected limb 15~30 degrees when resting or sitting to increase the venous return of the lower limb. Nowadays, the hospital uses endoscopic blood vessel extraction, which is less traumatic to the patient’s leg and has a faster recovery after surgery.