## What Causes Mountain Sickness?
Mountain sickness, often called altitude sickness or acute mountain sickness (AMS), is a common problem for people who travel to high places, especially if they go up quickly. It happens because the air gets thinner as you climb higher, which means there’s less oxygen in every breath you take. Your body needs oxygen to work properly, so when there’s not enough, it starts to struggle.
### Why Does Less Oxygen Cause Problems?
At sea level, the air pressure is high and there’s plenty of oxygen. As you go up a mountain, the air pressure drops and each breath contains fewer oxygen molecules. Your lungs have to work harder to get enough oxygen into your blood. If you climb too fast, your body doesn’t have time to adjust—this is called acclimatization—and that’s when symptoms of mountain sickness can start.
### The Science Behind Mountain Sickness
When your body senses low oxygen levels (a condition called hypoxia), it tries to adapt by making you breathe faster and deeper. Your heart beats faster too, trying to pump more blood around your body so that tissues get the oxygen they need. But if these changes aren’t enough—or happen too slowly—your brain and other organs start showing signs of stress.
Scientists think that low oxygen causes tiny blood vessels in the brain and lungs to leak fluid or become inflamed. This can lead to swelling in the brain (called cerebral edema) or fluid buildup in the lungs (called pulmonary edema). Both are serious conditions that need immediate medical attention.
### Who Gets Mountain Sickness?
Anyone can get mountain sickness if they go high enough and don’t give their bodies time to adjust. It doesn’t matter how fit or healthy you are; even athletes can be affected if they ascend too quickly. Some people seem more sensitive than others for reasons we don’t fully understand yet.
Children may be at higher risk because their bodies are still developing ways to handle stress like this. Older adults might also be more vulnerable due
