The reason for frequent sleepiness is the following: 1, because the blood viscosity is too high, when the body has hypertriglyceridemia, hypercholesterolemia and LDL blood is too high and blood viscosity is too high, especially to high density and high cut value of the main food will appear often sleepy situation. 2, in the body when the lack of oxygen will also appear often sleepy, especially when the brain cells are itchy sleepy is particularly significant. 3, often sleepy because of insufficient arterial blood saturation, carbon dioxide partial pressure is too high, oxygen partial pressure is too low and caused by the perimeter. This is due to the lack of oxygen saturation in the arterial blood, high partial pressure of carbon dioxide, low partial pressure of oxygen and caused by the lack of oxygen in the body. 3, the causes of frequent sleepiness and insufficient blood supply, often due to insufficient blood supply to the heart, cerebral arteries and insufficient blood supply caused by drowsiness, weakness, tiredness, accompanied by chest tightness, shortness of breath, dizziness and other symptoms. 4, such as anemia, low immunity, ion disorders, vitamin and trace element deficiency, also can cause frequent sleepiness.