Yawning is a normal physiological phenomenon that is often beyond your control. However, if you yawn too often, you should pay attention to it, especially if you are elderly. The reasons why older people yawn all the time include lack of oxygen to the brain, problems with vascular health, and fatigue and lack of sleep. Yawning is a manifestation of cerebral hypoxia. When a person is about to enter into a stressful work, he or she also often yawns one after another, and the body increases oxygen in the blood and expels more carbon dioxide through the deep breathing exercise of yawning, thus making people more energetic. Patients with hypertension or atherosclerosis, because the elasticity of the blood vessel wall is reduced, the blood flow to the brain is reduced, so they will often yawn to improve the blood supply to the brain cells. When the body is sleep deprived or overly fatigued, it will yawn one after another, which warns people that the brain and organs have become fatigued and need sleep and rest. Fatigue may seem like a trivial thing, but chronic fatigue that is difficult to recover from for a long time can destroy the body’s immunity, cause important organ lesions, and play a certain role in promoting cancer, so it needs to be given enough attention.