Will potato chips also cause "altitude sickness"? Why do snacks become swollen in the plateau?

China Science and Technology News Network, January 30 (Jin Xi) When you take a train from the inland to the plateau with potato chips, you will find that as the altitude increases, the potato chips become more and more swollen, and may even suddenly burst. This is the "altitude sickness" of potato chips.

The reason why potato chip bags expand when entering the plateau is because of the difference in air pressure. The air pressure inside the bag remains unchanged, but the ambient air pressure decreases, so the air inside the bag begins to expand. This phenomenon not only occurs in sealed packaged foods such as potato chips, bread, and instant noodles, but also in cosmetics. Some netizens said that the cosmetics they brought to Yunnan were sprayed all over their faces as soon as they opened them. To avoid this, you can open the package while the altitude is rising to allow the air pressure to balance. Just like people, after adapting for a period of time, the altitude sickness will be alleviated.

However, the human body will not expand, because the human body is not a closed environment. As a person breathes, the air pressure inside the human body will change with the change of the external air pressure. If the internal and external pressures are the same, expansion will not occur. Unless in an extreme environment, such as when the human body suddenly enters a vacuum state from a standard atmospheric pressure environment, the lungs may explode.

Many people do find that their limbs and even their faces become swollen when they arrive at the plateau, but this has nothing to do with the air pressure. This swelling is caused by edema due to lack of oxygen in the body, such as high-altitude pulmonary edema and cerebral edema.