At altitude, concentration of oxygen in the blood is low. People feel weak and unable to think properly. This disease is called…………….. .

Explanation

**Step-by-Step Solution:**

1. **Understanding the Context**: At high altitudes, the concentration of oxygen in the atmosphere is lower than at sea level. This affects how much oxygen can dissolve in the blood.

2. **Applying Henry's Law**: According to Henry's Law, the amount of gas that dissolves in a liquid is directly proportional to the partial pressure of that gas above the liquid. As altitude increases, atmospheric pressure decreases, leading to a lower partial pressure of oxygen.

3. **Consequences of Low Oxygen Levels**: With less oxygen available in the blood due to lower pressure, the body does not receive enough oxygen to function properly. This can lead to symptoms such as weakness and impaired cognitive function.

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