Mountain Sickness: What It Is and How to Handle It

If you’ve ever felt dizzy, nauseous, or short‑of‑breath after climbing a few thousand feet, you’ve probably experienced mountain sickness. Also called altitude illness, it happens when your body can’t get enough oxygen at higher elevations. The good news? Most people recover quickly with the right steps.

Common Symptoms to Watch For

The first sign is usually a headache that won’t quit, even after you’ve taken a pain reliever. Pair that with feeling woozy, nausea, or vomiting and you should start taking it seriously. Some folks get a rapid heartbeat, trouble sleeping, or swelling in their hands and feet—these are called peripheral edema.

Watch for more severe signs like confusion, loss of coordination, or a sudden drop in breathing ability. Those could mean high‑altitude cerebral edema (HACE) or pulmonary edema (HAPE), both medical emergencies that need immediate descent and professional care.

How to Prevent & Treat Mountain Sickness

The simplest rule is “climb slow, rest often.” Give your body time to adjust by limiting elevation gain to about 1,000 feet per day once you’re above 8,000 feet. If you feel any symptoms, stop moving, hydrate with water (avoid alcohol), and eat a light snack.

Medications can help too. Acetazolamide (Diamox) is commonly used to speed up acclimatization; a typical dose is 125 mg twice daily started a day before ascent. Over‑the‑counter pain relievers like ibuprofen or acetaminophen can ease headaches, but avoid NSAIDs if you have stomach issues.When symptoms persist for more than 24 hours or get worse, the safest move is to descend at least 1,000 meters (3,300 feet). Even a short walk downhill often brings relief because oxygen levels rise quickly.

Other practical tips: wear layers to stay warm, protect your skin from the sun, and keep a small emergency kit with a pulse oximeter if you have one. Knowing how to read your body’s signals makes the difference between an unforgettable adventure and a dangerous situation.