The manifestations of physical ischemia are as follows: 1. chronic ischemia: manifestation of circumferential weakness, drowsiness, body fatigue or easy to occur limb numbness symptoms; 2. acute ischemia: the manifestation of acute ischemia varies with different parts. If acute cerebral ischemia occurs, it manifests as dizziness, nausea, vomiting or inflexible movement of the lateral limbs. If precordial ischemia, it is manifested as episodic chest tightness, shortness of breath, and pain in the precordial area can be radiated to the left shoulder with a sense of near death, which can be relieved by taking nitroglycerin orally. If the digestive tract, gastrointestinal ischemia, manifested as abdominal pain, intestinal colic. Vascular ischemia in the extremities is manifested by coldness and pain at the end of the limbs and intermittent claudication after walking.