The normal range of Perfusion Index PI is about 4-5, which generally reflects the perfusion of blood flow. If the index is low, it means that there may be hypotensive shock, insufficient blood volume in the body or poor peripheral circulation and other factors. Generally, low perfusion index is accompanied by panic, chest tightness, dizziness, headache, weakness, weakness of limbs, sweating and other discomforts, so it is necessary to go to the hospital in time to improve the electrocardiogram, cardiac ultrasound, blood pressure and blood glucose measurement to rule out the occurrence of hypotension and hypoglycemia. Regular diet, avoid picky and partial food, drink a glass of light salt water every day, and ensure eight glasses of water every day. Ensure that the blood volume of water circulation in the body is sufficient to avoid dehydration or dehydration.