The influence of low pressure on human physiology mainly affects the supply of oxygen in human body. People need about 750 mg of oxygen every day, of which 20% is consumed by the brain, because the brain needs the most oxygen. When the natural air pressure drops, the oxygen partial pressure in the atmosphere, the oxygen partial pressure in alveoli and the arterial oxygen saturation all drop, which leads to a series of physiological reactions in human body. Take climbing from lowlands to mountains as an example. As the air pressure drops, the body accelerates breathing and blood circulation to make up for lack of oxygen, resulting in shortness of breath and increased heart rate. Due to the lack of oxygen in the human body, especially in the brain, dizziness, headache, nausea, vomiting, weakness and other symptoms will occur, and the nervous system will also be damaged, and even pulmonary edema and coma will occur, which is also commonly known as "mountain reaction."
In the high-pressure environment, the body tissues are gradually saturated with nitrogen (generally, after working under high pressure for 5-6 hours, the human body will be saturated with nitrogen). When the human body returns to the standard atmospheric pressure, the excess nitrogen in the body will be discharged with exhalation, but this process is slow. If you suddenly return to the standard atmospheric pressure environment from the high pressure environment, some nitrogen accumulated in fat may stay in the body, expand to form small bubbles, block blood and tissues, and easily cause diseases.
The influence of pressure change on human health is more manifested in the emergence, disappearance or movement of circulation weather situation represented by high pressure or low pressure. Under the situation of low-pressure circulation, it is mostly rainy and the wind direction changes obviously; Under the situation of high pressure circulation, it is mostly sunny and the weather is relatively stable. After several years of research, Japanese medical meteorologists found that the degree of hemoptysis and blood sputum aggravation of most tuberculosis patients is closely related to the low-pressure circulation weather. When the patient's condition worsens, 90% occurs in the case of low-pressure circulation, and more than half occurs in the process of low-pressure transport. However, under the condition of high pressure circulation, children's bronchitis and asthma are more likely to attack. When the high-pressure circulation moved to Japan, the number of asthma patients in Japan began to increase; After high pressure, the number of patients reached a peak; After the removal of high pressure, the number of asthma patients in Japan decreased significantly. The reason why this happens is that under the control of high pressure, the air is dry, the weather is fine, the wind is small, and radiation cooling at night is easy to form an inversion layer near the ground, and allergens such as dust, fungi, pollen and spores are easy to stay in the near ground, thus inducing asthma attacks.
At the same time, the change of air pressure will also affect people's psychological changes, making people feel depressed and depressed. For example, in rainy and snowy weather with low air pressure, especially in hot and humid weather before thunderstorm in summer (when the air pressure is low), people with poor cardiopulmonary function will feel extremely uncomfortable, and normal people will also feel depressed and uncomfortable. And this kind of suffocation and depression will make people's autonomic nerves tend to be nervous, release adrenaline, cause blood pressure to rise, heartbeat to accelerate, shortness of breath and so on. At the same time, cortisol is decomposed, which leads to an increase in gastric acid secretion, easy infarction of blood vessels and a sharp rise in blood sugar. Some scholars have made a comparative study of the lowest monthly pressure and the death peak, and found that 89% of the death peak occurred in the lowest monthly pressure.