At what altitude does altitude sickness start?

Related questions

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3. Does Caffeine Help altitude sickness?
4. Can we take a dip in Pangong Lake?
5. When should you worry about altitude sickness?
6. Why is Pangong Lake salty?
7. Can you get altitude sickness at 5000 feet?
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Tags

1. #sickness
2. #individual
3. #altitudes
4. #occur
5. #considerably
6. #travel
7. #usually
8. #occurs
9. #people
10. #lower
11. #higher
12. #altitude
13. #depending
14. #health