Guide to Altitude Sickness in the Annapurna Circuit Trek - Common Symptoms and Prevention Tips
As someone who has trekked the Annapurna Circuit, I can tell you firsthand that altitude sickness is no joke. Altitude sickness is a serious concern on the Annapurna Circuit Trek, especially when crossing the Thorong La Pass, which stands at a dizzying 5,416 meters (17,769 feet). Altitude sickness, also known as Acute Mountain Sickness (AMS), affects trekkers who ascend too quickly to high elevations without giving their bodies time to acclimatize.
Before my trek, I had heard countless stories about how altitude sickness forced trekkers to abandon their treks midway. To be honest, I was quite anxious about how my body would react to the high altitudes, especially after reaching the 3,000-meter altitude.
The trek started beautifully, with lush green forests, waterfalls, and picturesque villages making every step of the journey worthwhile. But as I ascended to higher altitudes, I began to feel the effects of thinner air. By the time I reached Manang, at around 3,540 meters, I started to experience mild symptoms of altitude sickness with headaches and shortness of breath.
Thankfully, I had come prepared. I had already planned for an acclimatization day in Manang, where I took the time to rest, hydrate, and explore the nearby trails to allow my body to adjust to the altitude. As I continued my ascent to Yak Kharka (4,050 meters) and Thorong Phedi (4,525 meters), I felt more confident and prepared, while other trekkers who hadn’t taken the necessary precautions were struggling with the symptoms of altitude sickness.
Although altitude sickness can be daunting, the Annapurna Circuit rewards you with stunning vistas and cultural experiences that make the effort worthwhile. To find out why so many trekkers choose this trek, check out my article 12 Best Reasons to Choose Annapurna Circuit Trek.
Altitude sickness can derail your trek if you’re not careful, but with the right strategies and precautions, you can prevent it from ruining your adventure. Here’s everything you need to know about preventing altitude sickness on the Annapurna Circuit Trek.
What is Altitude Sickness?
Altitude sickness, also known as Acute Mountain Sickness (AMS), happens when your body can’t adjust quickly enough to the decreased oxygen levels found at high altitudes. The Annapurna Circuit Trek exposes you to elevations ranging from 800 meters to over 5,000 meters, where the air becomes thinner, and your body has to work harder to get the oxygen it needs.
Altitude sickness typically occurs when you ascend too quickly without allowing your body time to acclimatize. Symptoms usually appear within 6 to 24 hours of reaching a higher altitude. Altitude sickness arises after at least four hours spent at an altitude above 2,000 m. The risk of altitude sickness increases significantly above 2,500 meters with a range of symptoms including headache and vomiting, which is why it’s critical to acclimatize properly. (Source: Better Health Channel).
AMS is not something to take lightly. Every year, trekkers underestimate its dangers, leading to serious health complications and even fatalities. This condition is significant and should not be ignored due to its potential to lead to severe complications, including high-altitude pulmonary edema (HAPE) and high-altitude cerebral edema (HACE), both of which can be life-threatening.
On the Annapurna Circuit, some of the highest-risk areas include Thorong Phedi (4,540 meters) and Thorong La Pass (5,416 meters). However, symptoms can start to appear at lower elevations, especially if you ascend too quickly or neglect proper acclimatization practices.
Common Symptoms of Altitude Sickness
Altitude sickness usually begins with mild symptoms that can escalate if left untreated. These symptoms include:
- Headache (the most common early sign)
- Nausea and vomiting
- Dizziness and light-headedness
- Loss of appetite
- Fatigue and weakness
- Shortness of breath
- Difficulty sleeping
If you begin to experience these symptoms while trekking, it’s crucial to take them seriously. Altitude sickness can quickly progress to more dangerous conditions like High Altitude Pulmonary Edema (HAPE) or High Altitude Cerebral Edema (HACE), which can be fatal if not addressed immediately.
How to Prevent Altitude Sickness on the Annapurna Circuit Trek?
Here are 9 ways to prevent altitude sickness on the Annapurna Circuit Trek.
1. Acclimatize Properly and Ascend Slowly
One of the most important things you can do to prevent altitude sickness on the Annapurna Circuit Trek is to give your body plenty of time to acclimatize. Acclimatization is the process of allowing your body to adjust gradually to the lower oxygen levels at higher altitudes.
A widely recommended acclimatization strategy is to "climb high, sleep low." This means that during the day, you may ascend to a higher altitude, but at night, you should descend to a lower altitude to sleep. This gives your body a chance to recover and adapt to the altitude while you rest. For example, when trekking to Manang (3,519 meters), many trekkers will hike up to nearby viewpoints or side trails that take them above 4,000 meters, but they return to Manang to sleep. This practice allows the body to experience higher altitudes during the day while resting at a lower elevation, which aids acclimatization.
Another important rule to follow when trekking at high altitudes is gradual acclimatization. It’s recommended not to increase your sleeping altitude by more than 300-500 meters per day once you’re above 3,000 meters. (Source: https://medlineplus.gov/ency/article/000133.htm).
This gives your body enough time to adjust to the lower oxygen levels without overexerting itself. On the Annapurna Circuit, Manang and Yak Kharka (4,050 meters) are excellent places to spend extra days to allow your body to acclimatize before continuing to higher altitudes.
2. Hydration
Staying hydrated is one of the simplest but most effective ways to prevent altitude sickness. Dehydration can minimize the symptoms of AMS, so it’s essential to drink plenty of water throughout your trek. At high altitudes, your body loses fluids more quickly through respiration and perspiration, so you need to drink more water than you would at sea level.
During the trek, you should aim to drink at least 3 to 4 liters of water per day to stay properly hydrated. Using a hydration bladder allows you to sip water continuously as you trek without having to stop and reach for a water bottle. Additionally, it’s best to avoid alcohol and caffeine, as both can dehydrate you and slow down the acclimatization process.
During my trek, I carried a reusable water bottle, which made it easy to refill and stay hydrated. I also made sure to drink water with my meals and avoid alcohol, which can slow down the acclimatization process.
3. Walk Slow and Steady
One of the biggest mistakes trekkers make is pushing themselves too hard and trekking too quickly. Trekking at high altitudes can be physically demanding, but it’s important not to overexert yourself. According to MSD Manuals, Overexertion is a significant risk factor for altitude sickness. Physical activity at high altitudes increases the body’s oxygen demand.
At high altitudes, it’s crucial to pace yourself and take your time. Trekking slowly allows your body to adjust to the altitude and reduces the risk of altitude sickness.
By moving at a slower pace, you conserve energy and reduce the strain on your body. High-altitude trekking is physically demanding, and rushing can drain your energy reserves, leaving you more susceptible to altitude sickness. Additionally, trekking at a slower pace allows you to take deeper breaths, ensuring your body gets the oxygen it needs.
In my experience, slowing down not only helped me avoid altitude sickness but also allowed me to fully appreciate the stunning scenery along the Annapurna Circuit.
4. Eat a Healthy Diet
At high altitudes, your body requires more energy to function, so it’s essential to eat a balanced diet that provides the necessary nutrients and calories. Carbohydrates are your body’s primary source of energy, and they are particularly important at high altitudes because they help your body use oxygen more efficiently. Dal Bhat (rice and lentils) is a common meal on the Annapurna Circuit that provides a good mix of carbs and protein.
Even if you don’t feel hungry due to the altitude, it’s important to eat regular meals to keep your energy levels up. Include protein and healthy fats in your diet to help you maintain your strength and endurance.
During the trek, I made sure to eat meals rich in carbs, like rice, potatoes, and bread, and I noticed that it helped keep my energy levels stable throughout the day. The tea houses along the Annapurna Circuit serve a variety of carb-heavy meals, such as "dal bhat" (lentils with rice), which is not only filling but provides the nutrients needed for sustained energy. Avoid skipping meals and aim to eat regular, balanced portions to keep your body fueled for the trek.
5. Consider Using Altitude Sickness Medications
For some trekkers, medication can be a helpful tool in preventing altitude sickness, especially if they have a history of AMS or are particularly concerned about it. Diamox (Acetazolamide) is a medication commonly used to prevent and treat altitude sickness. It works by speeding up the acclimatization process, helping your body adjust to the altitude more quickly. However, it should be used under the guidance of a doctor, and it’s important to start taking it a day or two before ascending to high altitudes.
I consulted my doctor before the trek and was prescribed Diamox. I started taking it a couple of days before reaching Manang, and I found that it helped me acclimatize more easily. However, I made sure to combine it with other preventative measures like staying hydrated, pacing myself, and acclimatizing properly.
6. Recognizing the Symptoms of AMS Early
The key to preventing serious complications from altitude sickness is recognizing the symptoms early and taking action. If you start to experience mild symptoms of AMS, it’s essential to stop and allow your body to acclimatize before continuing. If you start experiencing symptoms like headaches, dizziness, or nausea, stop trekking and take a break. Pushing through can make the symptoms worse. If the symptoms are mild, stay at your current altitude for a day or two to allow your body to adjust.
Don’t ascend to a higher elevation until the symptoms have become less intense. If the symptoms worsen or don’t improve after resting, the safest course of action is to descend to a lower altitude.
7. Avoid Smoking and Alcohol
Smoking and alcohol are both known to increase the risk of altitude sickness. Smoking reduces the amount of oxygen your body can take in, while alcohol dehydrates you and affects your body’s ability to acclimatize. Smoking constricts blood vessels and impairs lung function, limiting your body’s ability to take in the already reduced oxygen levels. This can lead to increased breathlessness, fatigue, and an elevated risk of developing AMS.
While it may be tempting to celebrate with a glass of beer or a shot of alcohol after a long day of trekking, alcohol consumption at high altitudes can severely affect your ability to acclimatize. Alcohol dehydrates your body, which is particularly dangerous when you’re trekking at altitudes where staying hydrated is crucial.
By avoiding smoking and alcohol, you not only reduce your risk of altitude sickness but also improve your overall trekking experience. The higher you go, the more your body will thank you for making smart choices.
If you're planning to embark on the Annapurna Circuit, make sure you're fully prepared to prevent altitude sickness by following the guidelines outlined in this article. Consider consulting with an experienced trekking company or guide to ensure your safety and maximize your chances of completing the trek. The Annapurna Circuit is a once-in-a-lifetime adventure, and with the right strategies, you can make it a safe, successful, and unforgettable experience.
8. Keep Your Head Covered and Dress in Layers
As you ascend to higher altitudes, the weather can become significantly colder, and it’s essential to protect your body from the cold to prevent any additional strain. Cold temperatures can constrict blood vessels and make it harder for your body to acclimatize. Wear a warm hat or headband to prevent heat loss from your head.
Dressing in layers is also key. Trekking at high altitudes often means dealing with rapidly changing weather conditions, from sunny mornings to chilly afternoons and cold nights. Layering allows you to adjust your clothing to stay warm and dry, which is essential for maintaining your body’s ability to acclimatize. Overexertion in the cold can also increase your chances of developing altitude sickness, so maintaining a comfortable body temperature is important.
9. Practice Breathing Exercises
Learning and practicing specific breathing techniques can improve your body's oxygen intake at high altitudes. Diaphragmatic or deep breathing helps expand your lungs and increases oxygen flow, which can be especially helpful when the air is thin. Focus on taking slow, deep breaths to fully inflate your lungs and get the most oxygen with each breath.
During my Annapurna trek, I practiced deep breathing exercises every morning before setting off for the day and every night before getting a sleep. It made a noticeable difference in how well my body handled the altitude, especially during steep climbs. Some trekkers use alternate-nostril breathing, a yoga technique that helps regulate breath and improve oxygen flow.
Conclusion
If you're planning to embark on the Annapurna Circuit, make sure you're fully prepared to prevent altitude sickness by following the guidelines outlined in this article.
Altitude sickness is a serious concern on the Annapurna Circuit, but with proper preparation and precautions, you can significantly reduce your risk and enjoy the breathtaking beauty of the Himalayas. By acclimatizing properly, staying hydrated, pacing yourself, eating well, and recognizing the symptoms of AMS early, you can have a safe and successful trek.