When you feel symptoms of altitude sickness, your body is reacting to getting less oxygen out of the thinner air that exists at higher altitudes than your body is used to. You can try multiple methods to prevent altitude sickness. The right option for you may depend on your situation. Here are the top tips from experts. Health Information and Medical Information - Harvard Health Discover the complete altitude sickness guide covering symptoms, causes, prevention tips, treatment options, and when to descend. Stay safe at high altitude! Altitude sickness, the mildest form being acute mountain sickness (AMS), is a harmful effect of high altitude, caused by rapid exposure to low amounts of oxygen at high elevation. [1][2][3] People's bodies can respond to high altitude in different ways. NHS information about altitude sickness, including symptoms, treatment and how to prevent it. Learn how to prevent altitude illness among international travelers visiting high altitudes. Traveling to a place at a higher elevation than you're used to can make you sick. Learn the symptoms of altitude sickness and what to do if you get it. Altitude sickness is the term for medical conditions that can happen when you move to a higher altitude too quickly. The higher up you go, the thinner the atmosphere gets. That means breathing in the same amount of air gets you less oxygen than at a lower altitude. Altitude sickness is our body's response to the low air pressure and oxygen typically occurring at altitudes over 8,000 ft. [1] If you know that you are going to be traveling to high altitudes, follow a few simple steps to prevent altitude sickness.