How is it that it is difficult to breathe in rainy or sultry weather?

in rainy or muggy weather, the air pressure decreases. The influence of low pressure on human physiology mainly affects the supply of oxygen in human body. People need about 75 mg of oxygen every day, of which 2% is consumed by the brain, because the brain needs the most oxygen. When the natural air pressure drops, the partial pressure of oxygen in the atmosphere, the partial pressure of oxygen in alveoli and the arterial oxygen saturation all drop, which leads to a series of physiological reactions in human body. 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 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.