Altitude Sickness Symptoms: A Guide for Visitors and Skiers in Colorado

The most common altitude sickness symptoms are a headache plus one or more of nausea, tiredness, dizziness, poor appetite and trouble sleeping, usually starting within a day of arriving somewhere high. In Colorado that often means the first night in a mountain town after flying into Denver. Most cases are mild and ease with rest, fluids and time, but altitude sickness can become serious, and the warning signs are worth knowing before you go.

What is altitude sickness?

Higher up, the air holds less oxygen with each breath. Your body adjusts over a few days, but if you climb faster than it can adapt, you can get acute mountain sickness, the common mild form. Denver sits at about a mile high, and some visitors notice mild effects here. Many ski towns and resorts are much higher, often above 8,000 feet, which is where altitude sickness becomes more common.

Fitness doesn't protect you. Fit, healthy people get altitude sickness too, and it's hard to predict who will. Having had it before is one of the better clues that you might again.

Altitude sickness symptoms to watch for

• Headache, often the first sign
• Nausea, vomiting or loss of appetite
• Unusual tiredness or weakness
• Dizziness or lightheadedness
• Poor sleep, waking often

These can feel a lot like a hangover or the start of a virus, which is why altitude sickness is easy to dismiss. If you've just gone up in elevation and feel this way, assume it's the altitude until proven otherwise. In children who can't describe a headache, look for fussiness, poor appetite and unusual sleepiness.

How to lower your risk before a ski trip

• Go up gradually. If you're flying in, spending a night in Denver before driving to the mountains gives your body a head start.
• Take the first day easy. Save the hardest skiing or hiking for later in the trip.
• Drink water regularly. The mountain air is dry and you lose more fluid breathing it.
• Go light on alcohol for the first couple of days, and avoid sleeping pills unless a clinician has said they're fine at altitude.
• If you have a heart or lung condition, are pregnant, or have had altitude sickness before, talk to a clinician before the trip.

Is there altitude sickness medication?

Yes. There are prescription medicines, acetazolamide being the best known, that can help some people prevent altitude sickness or ease it. They aren't right for everyone and have side effects and interactions worth discussing. If you've had altitude sickness before or are going very high, see a clinician before your trip to talk about whether one makes sense for you. Over-the-counter pain relievers may help a headache, but they don't treat the altitude itself, and feeling better from a pill is not a reason to keep climbing.

What to do if you feel sick at altitude

Don't go any higher until symptoms are gone. Rest, drink fluids and avoid alcohol. Mild symptoms often settle within a day or two as your body adjusts. If they get worse, or don't improve with a day of rest, go down. Descending even a couple of thousand feet often helps quickly. While you're in the mountains, use local medical care there.

Back in Denver and still unwell, or vomiting so much you can't keep fluids down? Come in for a sick visit. A clinician can examine you, look for other causes, and discuss treatment, which may include IV fluids for dehydration if you need them. IV fluids treat dehydration; they aren't a cure for altitude sickness itself.

What does a visit cost?

We contract with all major commercial and government plans, including Colorado Medicaid and Medicare. We can't guarantee that every commercial plan, especially an out-of-state one, has us in network; if your visit turns out to be out of network or your benefits are denied, you pay our self-pay rates. Self-pay in-clinic visits are $175, $250 with one moderate service, or $330 for a procedure or two moderate services, and never more than $330. Details are on the cost and insurance page.

Call 911 or go to the ER if… someone at altitude becomes confused, unusually drowsy or hard to wake, clumsy or unable to walk in a straight line; has a severe headache that keeps getting worse; is short of breath while resting; has a persistent cough, especially with frothy or pink-tinged mucus; has chest tightness or blue-gray lips; or faints. These can be signs of fluid on the brain or lungs. Get them down to a lower elevation and to emergency care right away, and don't let them go down alone.

Where to find us

Four clinics across metro Denver, all ages welcome, se habla español:

• Hampden (Southeast Denver): 8 AM–11 PM daily
• Littleton: 8 AM–11 PM daily
• Thornton: 8 AM–11 PM daily
• Highlands: Mon–Fri 5–11 PM, Sat–Sun 8 AM–11 PM

Walk in, or book online.