When Does Mountain Sickness Start?

Symptoms of altitude sickness usually develop between 6 and 24 hours after reaching altitudes more than 2,500m above sea level. Symptoms are similar to those of a bad hangover and include: headache.

Can you get altitude sickness at 5000 feet?

When changes in altitude overpower our ability to acclimatize, we can end up with high altitude illness. This can occur at elevations as low as 4-5,000 feet (the city of Denver, Colorado). More commonly, it develops at an altitude of approximately 8,000 feet or above.

At what elevation does altitude sickness begin?

Any time you go above 8,000 feet, you can be at risk for altitude sickness.