If yawning and tears are frequent, there are usually several factors as follows: First, the most common factor is the lack of oxygen in the brain. When the brain cells are deprived of oxygen, the ratio of ventilation and blood flow is usually severely imbalanced due to pulmonary insufficiency, and the oxygen saturation of arterial blood in the body decreases at this time, and the partial pressure of carbon dioxide is too high and the partial pressure of oxygen is too low. Second, when the blood supply to the large arteries is insufficient, there will also be frequent yawning accompanied by watery eyes, such as coronary ischemic heart disease, coronary artery insufficiency of blood supply and weakness caused by the body, there will also be yawning clinical symptoms. Third, the clinical symptoms of frequent yawning and watery eyes may also occur when the body is suffering from high blood viscosity or blood stickiness, usually hypertriglyceridemia and hypercholesterolemia.