What Are the Risks of High-Altitude Trekking, and How Can I Avoid Altitude Sickness?

If you’re planning an adventure trek in high-altitude regions, understanding the risks involved and how to prevent altitude sickness is essential. Over the last seven years, I’ve led international expeditions and spent considerable time above 3,000 metres (9,800 feet) – and I can confidently say that while the high-altitude environment is one of my favorites, it demands respect and preparation. The vistas above 4,000 metres (13,100 feet) are unforgettable, but altitude can bring discomfort, danger and, without proper management, altitude sickness.

Altitude sickness, or acute mountain sickness (AMS), happens when the body struggles to adjust to low oxygen levels at higher altitudes. If symptoms are ignored, the risks can become severe so it’s crucial to recognize why this happens and how to manage it. Let’s dive into what happens at high altitudes, the types of altitude sickness, and top strategies for prevention.

What Happens at High Altitudes?

High-altitude environments are defined by lower air pressure and reduced oxygen levels. This shift means your body has to work harder to get enough oxygen to function properly, which often causes symptoms like headaches, dizziness, and fatigue. Most people start experiencing these symptoms at around 3,000 metres, but some may feel them at even lower altitudes.

Popular trekking destinations like the Inca Trail, Mount Toubkal, and Everest Base Camp reach elevations over 4,000 metres, making altitude sickness a real possibility. Studies show that up to 43% of trekkers on routes like Everest Base Camp develop altitude-related symptoms, highlighting the importance of acclimatisation and risk awareness.

Types of Altitude Sickness

When you’re trekking at high altitudes, there are three main types of altitude sickness to be aware of:

1. Acute Mountain Sickness (AMS): This is the most common and the mildest form of altitude sickness, with symptoms such as headaches, nausea, dizziness, fatigue, and difficulty sleeping.

2. High-Altitude Pulmonary Edema (HAPE): HAPE is a serious, life-threatening condition where fluid builds up in the lungs. Symptoms include shortness of breath, chest tightness, and coughing, sometimes with frothy sputum. Immediate descent is necessary.

3. High-Altitude Cerebral Edema (HACE): This severe condition causes swelling in the brain and can lead to confusion, loss of coordination, and coma. HACE requires urgent descent and medical attention.

Key Risk Factors for Altitude Sickness

While anyone can experience altitude sickness, certain factors increase the risk:

• Rapid Ascent: Climbing too quickly without allowing your body to adjust is a common cause.

• Previous History of Altitude Sickness: Those who’ve experienced altitude sickness before are more likely to encounter it again.

• Genetic Predisposition: Some people are naturally more sensitive to altitude changes.

• Sleeping Altitude: Sleeping at a high elevation can exacerbate symptoms as breathing rates drop during sleep, reducing oxygen intake.

Top Tips to Avoid Altitude Sickness

The good news is that with the right strategies, you can reduce the risk of altitude sickness and make the most of your high-altitude adventure. Here’s how:

1. Acclimatise Gradually

Slow ascent is the best way to give your body time to adapt. Use the “climb high, sleep low” method, where you trek to higher altitudes during the day but descend to sleep lower. This method allows the body to acclimate to the altitude safely.

For example, on the Inca Trail, spending a few days in Cusco (3,400 metres or 11,150 feet) before the trek lets your body adapt. Aim to spend two or three days at high altitudes before starting your journey.

2. Stay Hydrated

Proper hydration is essential at high altitudes, as dehydration can worsen altitude sickness symptoms. Make sure to drink plenty of water, but avoid alcohol and caffeine as they can contribute to dehydration.

3. Monitor Your Health

Regularly check how you’re feeling, especially if symptoms of AMS arise. Ignoring mild symptoms can lead to complications. Using a pulse oximeter to monitor your blood oxygen levels can be helpful.

4. Consider Medication

Certain medications, like acetazolamide (Diamox), may help prevent altitude sickness by promoting faster acclimatisation. However, it’s best to consult your doctor before starting any medication, especially if you have pre-existing conditions.

5. Know When to Turn Back

If symptoms worsen, especially signs of HAPE or HACE, descending is often the best option. Even a few hundred metres can make a significant difference. Make sure you’re trekking with an experienced guide who understands altitude risks and knows when a descent is necessary.

Lessons from Everest Base Camp

Having led multiple treks to Everest Base Camp, I’ve witnessed the effects of altitude first-hand. I always feel the impact of altitude – headaches and breathlessness are common even after years of experience. While these symptoms indicate your body is adapting, more severe cases need to be monitored. In some cases, we’ve had trekkers descend or take a day off to acclimatise.

At Ultimate Adventure Travel, we build additional acclimatisation days into our itineraries, but it’s still important to listen to your body and not push beyond what feels safe.

Partnering with The Altitude Centre

We at Ultimate Adventure Travel have partnered with The Altitude Centre in London. The center offers pre-trip testing to see how well your body handles altitude and provides training plans to improve your response to lower oxygen environments. This can be a great step to reduce the risk before heading to higher altitudes.

If you’re interested in optimising your altitude tolerance, reach out, and we can help you connect with The Altitude Centre for a tailored pre-trip program.

Final Thoughts

High-altitude trekking offers some of the most awe-inspiring views and memorable experiences on earth. However, the risk of altitude sickness is real, and preparation is key to having a safe, enjoyable adventure. By taking the time to acclimate, staying hydrated, monitoring symptoms, and knowing when to descend, you can reduce your risk of altitude sickness and ensure you’re able to fully appreciate the journey.

Every body reacts differently, so remember to listen to yours. Your health is the priority – the mountain will always be there!