Yawning makes people get the best rest physically and psychologically, which has an important physiological protection effect on the human body. Some people think that yawning is a manifestation of brain hypoxia. By yawning and taking a deep breath, the human body increases oxygen in the blood and discharges more carbon dioxide, thus making people more energetic. When people are sleepy, they often yawn constantly to remind people that their brains are tired and need sleep and rest, so yawning is also a hypnotic method. People often yawn repeatedly when they are about to enter a stressful job. This may be because the human body increases more oxygen in the blood through deep inhalation and improves the activity ability of the brain. In a word, yawning is an instinctive reaction of human body, just like heartbeat and breathing, which is not controlled by human will. It has a good protective effect on protecting brain cells, increasing oxygen supply to brain cells and improving human stress ability. After intense study, you often open your arms and give a long yawn. At this time, your chest will have a comfortable feeling. Do you know what benefits yawning has on human body? In the process of intense study, people's nervous system will consume more energy and produce a lot of carbon dioxide. Calm breathing can't expel carbon dioxide from the body in time. Excessive accumulation of carbon dioxide in the body will cause chest tightness and fatigue of various organs of the body. Because the carbon dioxide in the blood is higher than the normal level, it will stimulate the respiratory center and make people take a deep breath-yawn. Yawning can not only expel excessive carbon dioxide from the body, but also be a protective adaptation of the human body. When the human body is short of sleep or overworked, it will yawn one after another. This is to warn people that their brains and organs are tired and ask us to go to bed and have a rest. Yawning often after getting up in the morning can promote the functional area of the cerebral cortex from inhibition to excitement, so that the cerebral cortex can work normally. Yawning is a beneficial physiological reaction of human body, but it is also an alarm of physical diseases. The main cause of frequent yawning is cerebral ischemia and hypoxia. Clinical studies have found that about 70%~80% of patients with ischemic stroke will yawn frequently due to cerebral ischemia and hypoxia about a week before onset. The reason is that middle-aged and elderly people, especially those with hypertension and cerebral arteriosclerosis, suffer from atherosclerosis, narrowing the lumen and decreasing the elasticity of the blood vessel wall, which leads to a decrease in blood flow to the brain, while the brain is very sensitive to oxygen, accounting for only about 2% of the body weight, but consuming about 25% of the whole body oxygen demand. Therefore, yawning often occurs during cerebral ischemia and hypoxia. In addition, yawning can also reduce the pressure in the chest cavity, increase the amount of blood flowing back to the heart from the superior and inferior vena cava, increase the output of the heart, and improve the blood supply ability of brain cells. But this improvement is temporary, so frequent yawning often indicates that ischemic stroke may occur in the near future. Therefore, middle-aged and elderly people, especially patients with cardiovascular and cerebrovascular diseases, often yawn without inducement. Never take it lightly. We should go to the hospital for examination in time and actively treat hypertension and hyperlipidemia under the guidance of doctors. Rest when you are tired; It is also possible that you often yawn, indicating that your body function is not good ~ ~ Exercise more ~ At the same time, pay attention to consciously cultivate your attention and gradually solve the problem of yawning ~ And ordinary yawning is a symptom of the hypothalamus secreting exciting sex hormones (that is, it is not exciting to pull up), which is a way to remind your physical or mental activities to last too long (too intense). Don't worry too much, just rest more. When people feel tired, they often yawn. The deep breathing effect of yawning increases the inhalation of oxygen, which can temporarily relieve people's fatigue. ? "This is a way of spontaneous regulation by the brain," explained Ronald Beringer, a psychologist at Temple University. He once did an experiment in which the tester put on a special watch and asked them to press the button on the watch every time they wanted to yawn and record it. Two weeks later, he found that people yawn more frequently before they are ready to do "big things", such as when marathon runners are about to go on the road, when soloists are on stage, and before students enter the examination room. Ronald therefore believes that people need to yawn to maintain a certain degree of psychological vigilance. The same phenomenon happens in the opposite situation, that is, when people relax in leisure, they will keep yawning. Ronald believes that this is due to the lack of external stimuli, and the human body can only maintain a normal state of excitement through self-motivation. But psychologists have not found a reasonable explanation to explain why many people often yawn before going to bed. As for yawning, it will make people feel very comfortable. Psychologists believe that this is not because of supplementing oxygen, but because yawning encourages more blood to flow to the brain. Is based on the obvious increase in the frequency of yawning after a full meal. This is because when the blood in the body gathers in the stomach, the brain will "protest" and take necessary self-protection measures. When the brain nerve is damaged, it will lose this ability to protect itself. For example, schizophrenics never yawn. Psychologists believe that yawning "contagion" will inevitably occur when the human body is in the same state, and the eyesight or hearing can be reached, indicating that different individuals have the same needs at a certain moment, and the actions of their peers "remind" themselves to keep "synchronized" with others. After a deep sleep, primate gorillas are always the first young male gorillas to wake up, stretching their arms, moving their legs and yawning loudly, so all gorillas open their eyes together and start to go out for food. Yawning is unpredictable and difficult to suppress, but in order not to appear rude, it is best to cover your mouth with your hand when yawning in public, which is considered as a sign of education. When yawning, it will give others a hint: people who are sleepy and lack of oxygen in the brain will yawn reflexively.