Altitude sickness which includes nausea, fatigue and heart palpitations occurs due to

Options

A. High atmospheric pressure at high altitudes
B. Low atmospheric pressure at high altitude
C. High mountain height and high temperature
D. Heavy snowfall at high altitude and low temperature

Answer

**Step-by-Step Solution:**

1. **Understanding Altitude Sickness**: Altitude sickness is a condition that arises when individuals ascend to high altitudes too quickly. It is characterized by symptoms such as nausea, fatigue, and heart palpitations.

2. **Identifying Causes**: The primary cause of altitude sickness is the decrease in atmospheric pressure as one ascends to higher altitudes. This leads to a lower availability of oxygen in the air.

3. **Analyzing Options**:
- **Option 1**: High atmospheric pressure at high altitude - This is incorrect because atmospheric pressure decreases as altitude increases.
- **Option 2**: Low atmospheric pressure at high altitude - This is correct as it directly relates to the reduced oxygen availability, leading to hypoxia.
- **Option 3**: High mountain height and high temperature - This is incorrect; while high mountain height is relevant, high temperature does not contribute to altitude sickness.
- **Option 4**: Heavy rainfall at high altitude and low temperature - This is also incorrect; while low temperatures can occur at high altitudes, they do not directly cause altitude sickness.

4. **Conclusion**: The correct answer is that altitude sickness occurs due to low atmospheric pressure at high altitude, which results in insufficient oxygen (hypoxia) leading to symptoms like nausea and fatigue.

**Final Answer**: Altitude sickness occurs due to low atmospheric pressure at high altitude.

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