Generally, if the blood supply to the brain is insufficient, the brain will yawn if it lacks oxygen. Get up and exercise, or do something with high concentration, but still pay attention to rest. As the saying goes, early to bed and early to rise makes you energetic. It is caused by physical fatigue. When I say fatigue, I don't mean lack of sleep or overwork, because when the activity of immune cells in our body functions drops, we will feel sleepy and yawn, which is a manifestation of sub-health. Sub-health is only one step away from health, and sub-health is only one step away from disease. So don't underestimate the usual adverse reactions, pay attention to the usual health care, and ensure a reasonable diet and balanced nutrition. Among them, vitamins and minerals are essential nutrients for human body; The human body cannot synthesize vitamins and minerals, but vitamins C, B and iron are particularly important to the human body, so it is necessary to supplement multivitamin tablets properly every day. Adjust mental state and keep positive and optimistic; Adjust the law of life in time, combine work and rest to ensure adequate sleep; Increase outdoor physical exercise activities and ensure a certain amount of exercise every day; The vast majority of mental workers exercise less and eat less on weekdays, and eat more and more refined foods. The intake of vitamins and various minerals is often difficult to meet the needs. In order to get rid of sub-health as soon as possible, it is suggested that these people take a certain amount of vitamin and mineral supplements every day. The daily expenses are not much. For example, Jin Shikang, an old-fashioned multivitamin that has been on the market for more than ten years, can effectively supplement vitamins A, B, C, D, E, folic acid, calcium, phosphorus, magnesium, iodine, iron, zinc and other minerals for only one yuan a day, which is helpful to improve physical fitness, enhance resistance and comprehensively consolidate health foundation. Therefore, actively supplementing nutrition is also an effective way to help you stay away from sub-health. Pay attention to the conditioning of sleep and rest habits, let the brain enter the biological clock state, and pay attention to some drug treatment. If the friend who asks this question often yawns after sleeping enough, I suggest you check the blood viscosity to see if the blood is sticky. It is also possible that intracranial pressure is increased, and the reason should be investigated. Excluding these, other possible causes are not too harmful.