Medication for preventing and treating altitude sickness

Acetazolamide is commonly prescribed to help the body acclimatise and may be started before ascent in travellers at increased risk. Dexamethasone may be used in selected circumstances, including when acetazolamide is unsuitable or as part of urgent treatment, but it does not produce acclimatisation and requires clinical guidance.

Rapid travel to high altitude gives the body less time to adjust to lower oxygen availability. Acute mountain sickness often presents with headache plus nausea, dizziness, fatigue, poor appetite, or disturbed sleep after ascent. Fitness does not reliably prevent it, and symptoms should guide decisions about going higher.

Severe altitude illness can affect the brain or lungs. Confusion, loss of coordination, breathlessness at rest, chest tightness, blue or grey lips, or a wet cough are warning signs. Medication should never be used to mask these symptoms so that ascent can continue.

Discuss your route, sleeping altitude, speed of ascent, previous altitude reactions, medical conditions, allergies, pregnancy status, and regular medicines during a travel health consultation. A clinician can decide whether preventive medication is appropriate and explain when to start and stop it. Do not borrow another traveller's prescription.

Acetazolamide can cause tingling in the fingers or toes, increased urination, and altered taste. Tell the prescriber about kidney or liver problems and any previous serious medicine reaction. Dexamethasone has different risks and must be taken only according to the prescribed plan; stopping or extending it without advice can be unsafe.

Ascend gradually, avoid going higher while symptomatic, and allow recovery time. For mild symptoms, stop ascent, rest, stay hydrated without forcing excessive fluids, and use only medicines that are safe for you. Resume climbing only after symptoms have resolved.

Descend and seek urgent medical help if symptoms worsen despite rest, or if there is confusion, unusual drowsiness, inability to walk steadily, breathlessness at rest, coughing up frothy fluid, or blue or grey coloration around the lips. Use oxygen and prescribed emergency medication if available and trained to do so, but do not delay descent while waiting for improvement.

A person with severe symptoms should not descend alone. Contact local rescue or emergency services, keep the person warm, limit exertion, and move to a lower altitude as safely and quickly as conditions permit.

Ask how your itinerary affects your risk, whether acetazolamide fits your health history, what side effects should prompt a call, and what to do if you miss a dose. Clarify which symptoms mean stop ascending, which require immediate descent, and how to access medical or rescue support along your route.