Denver Altitude: What's Actually True

Will I get altitude sickness in Denver?

Probably not. The CDC associates altitude illness with sleeping altitudes of 8,000 feet and above — and sometimes lower — while Denver sits at 5,280. Visitors more often notice that alcohol hits harder and the first night's sleep is poor, which is a different and much milder thing.

This is not medical advice, and people vary. If you have a heart or lung condition, or you are pregnant, your own doctor's guidance beats a travel guide's.

What does the CDC actually recommend at altitude?

Four things, none of which is the advice you usually hear: avoid alcohol for the first 48 hours, keep exercise mild for the first 48 hours, maintain your normal caffeine intake, and ascend gradually if you are heading higher.

• •Avoid alcohol for the first 48 hours — the CDC classes it as a respiratory depressant to avoid for sleep at altitude. This is the sourced version of 'drinks hit harder in Denver'.
• •Mild exercise only for the first 48 hours. A hard hike on day one is the classic mistake.
• •Do not skip your usual coffee. Caffeine withdrawal produces headaches that get misread as altitude sickness.
• •Ascend gradually. Going from sea level to a night above 9,000 feet in one day is a genuine risk; going to Denver is not.

Does drinking extra water help with Denver's altitude?

The CDC does not publish hydration guidance for altitude acclimatisation. The advice to drink far more water than usual in Denver is repeated everywhere but is not sourced to the CDC's altitude recommendations, which cover alcohol, exertion, caffeine and rate of ascent instead.

Drinking normally in a dry climate is sensible on its own terms. It is just not the altitude intervention it is usually presented as, and it tends to crowd out the guidance that is actually documented.

What does altitude sickness feel like?

Acute mountain sickness presents like a hangover: a headache plus at least one of appetite loss, dizziness, fatigue, nausea and occasionally vomiting. Onset is typically 2 to 12 hours after arriving at altitude, which is why it often gets blamed on the first night's sleep.

Above about 9,000 feet, periodic breathing during sleep becomes close to universal, and disturbed sleep is the most common complaint travelers report at high altitude. Again — these are mountain numbers, not Denver ones.

If symptoms are severe, or if someone becomes confused or unsteady on their feet at altitude, that is a reason to descend and seek medical care rather than to wait it out.

Where does altitude actually matter on a Denver trip?

In the mountains, not the city. A day trip to the high country can put you above 10,000 feet within ninety minutes of downtown, which is a different physiological situation from your hotel room in LoDo.

• •Red Rocks Amphitheatre sits at 6,400 feet — still below the CDC threshold, though its own FAQ calls the climb to the seats a challenging workout at that elevation. Westword puts the uphill walk from the Lower South lots at fifteen to thirty minutes, longer depending on your pace.
• •Mount Blue Sky, Loveland Pass and the ski resorts all put you well above 8,000 feet.
• •If you are sleeping in the mountains rather than day-tripping, that is when the CDC's gradual-ascent guidance applies to you.