Solutions & prevention
Medicines for Altitude sickness
Illness from going too high too quickly, where the air has less oxygen — usually mild, but occasionally serious, and largely preventable by ascending gradually.
Education and reference only. This explains which medicines are used and why, in plain language — it deliberately contains no doses and is not a substitute for advice from your doctor or pharmacist. Always discuss your own treatment with a qualified clinician, and check the BNF and the product labelling for prescribing detail.
Quick answer
What is Altitude sickness?
Altitude sickness happens when a person travels to a high altitude too quickly, before their body has had time to adjust to the lower level of oxygen in the air. It typically begins above around 2,500 metres and is common among trekkers, climbers and travellers to high places.
- How it is treated: The cornerstone of both prevention and treatment is a gradual ascent, giving the body time to acclimatise ("climb high, sleep low", limiting how much higher you sleep each night, and building in rest days).
- Self-care: Ascend gradually (limit how much higher you sleep each night, include rest days, "climb high, sleep low"), stay hydrated, avoid alcohol, and know the warning signs.
- When to seek help: For mild symptoms, stop ascending and rest.
What it is
Altitude sickness happens when a person travels to a high altitude too quickly, before their body has had time to adjust to the lower level of oxygen in the air. It typically begins above around 2,500 metres and is common among trekkers, climbers and travellers to high places. The most common form, acute mountain sickness, causes symptoms rather like a hangover — headache, nausea, tiredness, dizziness and difficulty sleeping — usually within hours of arriving at altitude. It is usually mild and improves with rest and not going higher. However, two serious and potentially life-threatening forms can develop: fluid on the lungs (HAPE), causing severe breathlessness and a cough, and fluid on the brain (HACE), causing confusion, unsteadiness and drowsiness. Recognising the warning signs of these serious forms is crucial, as they require immediate descent and emergency treatment. Altitude sickness is not related to fitness — anyone can be affected.
How it is treated
The cornerstone of both prevention and treatment is a gradual ascent, giving the body time to acclimatise ("climb high, sleep low", limiting how much higher you sleep each night, and building in rest days). For mild altitude sickness, the key is to stop ascending, rest, keep hydrated, and use simple pain relief for headache; symptoms usually settle in a day or two, after which ascent can resume cautiously. Crucially, if symptoms are severe or worsening, or there are signs of the serious forms (severe breathlessness, confusion, unsteadiness), the person must descend immediately, as descent is the most effective treatment, and seek emergency help; oxygen and specific medicines may be used. Certain medicines can help prevent or treat altitude sickness for some people and trips, discussed with a travel health professional beforehand. Planning a sensible ascent profile and knowing the warning signs are the most important measures.
For this condition, these medicines
Medicine classes used for Altitude sickness
Each links to a full, dose-free guide — what it is, how it works, who can and cannot use it, side effects, interactions and FAQs.
Beyond medication
Lifestyle and self-care
Ascend gradually (limit how much higher you sleep each night, include rest days, "climb high, sleep low"), stay hydrated, avoid alcohol, and know the warning signs. Discuss preventive medicines with a travel clinic for high trips. Descend if symptoms are severe or worsening.
When to get help
When to see a doctor
For mild symptoms, stop ascending and rest. Descend immediately and seek emergency help for severe or worsening symptoms, severe breathlessness or cough, confusion, unsteadiness or drowsiness — these can indicate life-threatening fluid on the lungs or brain.
Not sure how urgent it is? It is always OK to call NHS 111 for advice, day or night.
Answers
Altitude sickness: frequently asked questions
How do you prevent altitude sickness?
Mainly by ascending gradually to let your body acclimatise — limiting how much higher you sleep each night, including rest days, and "climbing high, sleeping low" — along with staying hydrated and avoiding alcohol. Preventive medicines help for some trips.
When is altitude sickness an emergency?
When symptoms are severe or worsening, or there is severe breathlessness and cough (fluid on the lungs) or confusion, unsteadiness and drowsiness (fluid on the brain). These need immediate descent and emergency treatment.
Sources
Where this is drawn from
- NHS — Altitude sickness
- TravelHealthPro — Altitude illness
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