Altitude Sickness: What Trekkers and High-Altitude Travellers Should Know

Heading to the Andes, the Himalayas or another high-altitude destination? Altitude sickness can affect fit, healthy travellers, not just inexperienced ones. This guide explains what causes it, how to spot it early and how our Travel Clinic in Wembley and Stonebridge can help you prepare. 

What is altitude sickness? 

Altitude sickness develops when you climb faster than your body can adjust to lower oxygen levels. It typically appears above 2,500 metres. It ranges from mild discomfort to a serious, potentially life threatening condition. Knowing the early signs can help you act before symptoms become more serious. 

What are the symptoms of altitude sickness? 

Common early symptoms include headache, nausea, dizziness and poor sleep. These usually appear within hours of reaching altitude. More serious warning signs include confusion, breathlessness at rest and a persistent cough. The NHS advises anyone with severe symptoms to descend and seek medical help promptly. 

How can you prevent altitude sickness? 

• Gradual ascent gives your body time to adapt, so it remains the most effective prevention strategy. Consider these steps: 

• Ascend slowly and avoid sleeping more than 300 to 500 metres higher than the previous night 

• Build rest days into longer treks 

• Stay well hydrated and limit alcohol 

• Avoid strenuous exertion on your first day at altitude 
• Discuss your itinerary with a travel health professional before you go, as preventative medication may suit some travellers

Who is most at risk? 

Risk depends more on ascent speed than fitness or age. Travellers with certain heart, lung or blood conditions may face added risk, so speaking to a travel health professional before your trip can be helpful. Anyone who has experienced altitude sickness before should seek tailored advice ahead of their next trip. 

Your pre travel appointment is also a good opportunity to check whether you need any other travel vaccines for your destination. Depending on your itinerary, these could include Hepatitis A or the combined Hepatitis A and Typhoid vaccine.

When should you seek medical help? 

Worsening symptoms, confusion or breathlessness at rest all need urgent attention. Descending to a lower altitude is often the safest first step. If symptoms persist or worsen, seek local medical care without delay. 

Plan ahead with our Travel Clinic in Wembley and Stonebridge 

A pre travel consultation lets our team assess your itinerary, health history and altitude plans. It also gives you the chance to discuss any vaccinations or preventative medication you may need before travelling. Book your appointment today. 

Frequently Asked Questions

What altitude does altitude sickness start at? 

Most cases begin above 2,500 metres, though sensitivity varies between individuals. Ascending gradually reduces your risk considerably. 

Can fit and healthy people get altitude sickness? 

Yes. Fitness does not prevent altitude sickness, as it relates to ascent speed rather than physical condition. 

How long do altitude sickness symptoms last? 

Mild symptoms often ease within a day or two of rest at the same height. Worsening symptoms need prompt medical attention. 

Is there medication to prevent altitude sickness? 

Some prescription options may help certain travellers. Discuss suitability with a prescriber during a pre-travel consultation. 

Where can I get pre-travel advice near Wembley? 

Book a consultation at our Travel Clinic, serving Wembley, Stonebridge and the surrounding areas of Brent and North West London.