Clinically, there is no such thing as a clean blood vessel. If the patient does not have symptoms related to arterial or venous blockage, such as cold limbs, angina, and swollen limbs, it means that the blood vessel is still healthy. 1. Clogged arteries (1) When the arteries of the limbs are clogged, there will be coldness, pale numbness, unbearable pain, intermittent claudication, etc., and even gangrene of the limbs will occur. (2) When the arteries of organs are blocked, such as renal artery blockage, renal hypertension, renal unit or whole kidney ischemic necrosis will occur, and eventually cause renal function damage. (3) When the arteries supplying blood to the brain are blocked, stroke and transient ischemic attack will occur. (4) Coronary artery blockage may result in myocardial infarction and angina pectoris. 2. Venous blockage (1) Deep vein thrombosis of the lower limbs, there will be swelling of the limbs, elevated body temperature, etc., and may be accompanied by anterior varicose veins. If there is no timely treatment, venous thrombus dislodgement will enter the femoral vein, external iliac vein, common iliac vein and so on along with the direction of the blood flow and stay in the right atrium, resulting in pulmonary embolism and ultimately causing respiratory circulatory disorders. (2) When superficial veins are blocked, symptoms of thrombophlebitis such as localized swelling, sclerosis, and streak-like changes in blood vessels may occur. It is recommended to go to the hospital for regular checkups to clarify the health condition.