Altitude sickness in Nepal affects many trekkers. Learn how to prevent it, recognize symptoms, and hear Sonia’s real experience from the trail.
Altitude Sickness in Nepal: What Every Trekker Needs to Know
Your complete guide to staying safe, smart, and confident at high altitudes.
1. Introduction
There’s something undeniably magical about trekking in Nepal. The air is crisp, the views are cinematic, and each step brings you closer to landscapes you once only saw in photos. Snow-draped Himalayan peaks rise like sentinels above the clouds. Prayer flags flutter in the wind. Ancient trails wind through villages where time moves slowly.
But for all its beauty, Nepal’s high-altitude regions also come with a unique challenge: altitude sickness.
Also known as Acute Mountain Sickness (AMS), altitude sickness is the great equalizer — it doesn’t care how fit you are, how young or experienced. It can affect seasoned climbers and first-timers alike. And when you’re trekking above 2,500 meters, understanding how altitude affects your body isn’t just useful — it’s essential.
At Resurgence Travel, we believe in equipping our trekkers with the knowledge and tools to experience the Himalayas safely and confidently. That includes understanding the risks of altitude, recognizing symptoms early, and knowing what to do if things don’t feel right.
This guide isn’t here to scare you — far from it. In fact, it’s meant to do the opposite. By the time you reach the end, our goal is for you to feel empowered, not anxious. Trekking at altitude is one of life’s most rewarding experiences, and with the right awareness, preparation, and guidance, you’ll be far better prepared to enjoy every moment.
We’ll explore what altitude sickness is, who’s at risk, how to prevent it, and what to do if it strikes. We’ll also share a real-life story from Sonia, one of our most experienced team members, who recently faced AMS head-on during a trek in Nepal.
Let’s begin with the basics — what exactly is altitude sickness, and why does it matter so much when you’re walking in the footsteps of the Himalayas?
2. What Is Altitude Sickness?
Altitude sickness — also known as Acute Mountain Sickness (AMS) — is your body’s natural reaction to ascending too quickly into areas where the oxygen level is significantly lower than what you’re used to.
At sea level, oxygen saturation in the air is about 21%. As you ascend, air pressure drops, which means each breath delivers fewer oxygen molecules to your bloodstream. This can put stress on your body, especially if it hasn’t had time to adapt.
AMS commonly occurs when trekkers or climbers ascend above 2,500 meters (8,200 feet) — a point where oxygen levels drop enough that your body needs to begin acclimatizing. While some people feel absolutely fine at this altitude, others may begin experiencing symptoms even below this threshold, depending on how fast they’ve ascended and how their body responds.
It’s important to understand that altitude sickness is not a reflection of your fitness, strength, or trekking experience. You could be a marathon runner and still experience AMS. In fact, physically fit people are sometimes more likely to suffer because they ascend faster, pushing harder with fewer rest stops.
There are three primary forms of altitude-related illness:
- Acute Mountain Sickness (AMS): The most common form. Symptoms can include headache, nausea, fatigue, dizziness, and difficulty sleeping.
- High-Altitude Pulmonary Edema (HAPE): A dangerous condition where fluid accumulates in the lungs. It can be fatal if not treated promptly.
- High-Altitude Cerebral Edema (HACE): The most severe form. It involves fluid buildup in the brain and is life-threatening if ignored.
Luckily, HAPE and HACE are rare — especially when you’re trekking with a well-paced itinerary, taking acclimatization days, and listening to your body. But awareness is key. Recognizing AMS early means you can take simple steps to prevent it from escalating into something more serious.
At its core, altitude sickness is your body saying, “Give me time to catch up.” And that’s something we take seriously at Resurgence Travel. Every one of our Nepal trekking itineraries is designed with smart pacing and proper acclimatization built in — because prevention is always better than evacuation.
In the next section, we’ll take a closer look at the symptoms you need to watch for when trekking at altitude — and how to tell if your headache is just from the trail, or something more.
3. Common Symptoms to Watch For
When you’re trekking in the Himalayas, it’s normal to feel a bit tired. After all, you’re walking long distances, sleeping in unfamiliar places, and adjusting to a new rhythm. But how do you tell the difference between normal trek fatigue and symptoms of altitude sickness?
It all starts with tuning in to your body — especially as you climb above 2,500 meters. Altitude sickness tends to sneak in gradually, and its early symptoms can be easy to dismiss. But if you catch it early, you can usually treat it with something as simple as rest and hydration.
Here are the most common signs of AMS (Acute Mountain Sickness):
- Headache: A dull, throbbing headache that won’t go away — especially if it worsens when lying down — is often the first and most reliable symptom of AMS.
- Nausea or loss of appetite: You might feel sick to your stomach or suddenly lose interest in food, even if you’ve been trekking for hours and should be hungry.
- Fatigue or unusual tiredness: Feeling more exhausted than the effort of the trek would normally cause? That’s a red flag.
- Dizziness or lightheadedness: Feeling wobbly or unstable while walking — especially when standing up quickly — can indicate oxygen deprivation.
- Difficulty sleeping: Many trekkers report restless nights, frequent waking, or vivid dreams as altitude increases.
- Shortness of breath (even at rest): It’s normal to breathe harder while hiking uphill, but if you’re struggling for air while lying in your sleeping bag, that’s something to pay attention to.
If you’re experiencing a combination of these symptoms, especially a persistent headache plus another symptom, it’s time to slow down — or even stop for the day. Don’t try to “push through it.” That mindset can lead to more serious complications.
What about more serious symptoms?
Altitude-related illness exists on a spectrum. AMS is the mild end — but if ignored, it can escalate to more serious conditions like:
- HAPE (High-Altitude Pulmonary Edema): Symptoms include a persistent dry cough, chest tightness, and breathlessness even at rest. It can come on suddenly and worsen rapidly.
- HACE (High-Altitude Cerebral Edema): This affects the brain and may cause confusion, hallucinations, extreme fatigue, and poor coordination (e.g. inability to walk in a straight line).
If you or someone in your group shows signs of HAPE or HACE, it’s critical to descend immediately and seek medical help. Both conditions can be life-threatening — but are also rare when proper acclimatization protocols are followed.
Next, we’ll look at who is most at risk of altitude sickness — and why it’s not always who you’d expect.
4. Who Is at Risk?
One of the most common misconceptions about altitude sickness is that it only affects people who are unfit or unprepared. In reality, altitude sickness doesn’t discriminate.
It can affect young trekkers, older adventurers, marathon runners, yoga instructors, and even seasoned climbers. In fact, some of the most experienced travelers have been caught off guard simply because they assumed they’d be immune.
The truth is, altitude sickness is less about how strong or fit you are, and more about how your individual body adapts to reduced oxygen levels. And unfortunately, there’s no reliable way to predict how you’ll respond until you’re up there.
Here are some common risk factors:
- Rapid ascent: Going up too quickly is the #1 trigger. Trekking itineraries that don’t allow for acclimatization days put you at much greater risk.
- Previous altitude sickness: If you’ve had AMS before, you may be more prone to it again — though not always.
- Sleeping at high altitude: Spending the night at elevations above 3,000 meters increases the chances of developing symptoms.
- Ignoring early warning signs: Pushing through a headache or mild nausea can allow things to escalate into more serious illness.
Interestingly, people who are very fit may actually be at higher risk — not because of their physiology, but because they tend to ascend faster and take fewer rest breaks. Slowing down, even if you feel capable of more, is one of the smartest things you can do at high altitude.
And here’s some encouraging news: your body can adapt. Acclimatization is a powerful process, and when done right, it significantly reduces your risk. That’s why Resurgence Travel builds in buffer days for rest, hydration, and gradual adjustment — especially on treks like the Everest Base Camp or Annapurna Circuit.
In the next section, we’ll dive deeper into what you can do to prevent altitude sickness — because while it may be unpredictable, it’s absolutely manageable with the right approach.
5. How to Prevent Altitude Sickness
The good news is that altitude sickness is highly preventable. While no one can guarantee how their body will react to thinner air, there are proven strategies to reduce your risk and give yourself the best possible chance of trekking safely and comfortably at altitude.
Here’s what we recommend — and what’s built into every Resurgence Travel trekking itinerary:
1. Take Your Time: Slow and Steady Wins at Altitude
The single most important thing you can do is ascend gradually. Trekking too fast is the most common reason people get sick. Your body needs time to adjust to lower oxygen levels, and the only way it can do that is with rest and patience.
- Rule of thumb: Don’t ascend more than 300–500 meters per day once you’re above 2,500m.
- Acclimatization days: Always plan rest days into your itinerary — especially before big elevation jumps (e.g. Namche Bazaar or Dingboche on EBC).
At Resurgence Travel, we never cut corners here. Our routes are purposefully designed with rest stops, flexible pacing, and safe overnight elevations.
2. Climb High, Sleep Low
This old mountaineering principle means you can safely explore higher altitudes during the day, as long as you return to sleep at a lower elevation. It’s a powerful way to trigger acclimatization without overstressing your body.
For example: On day hikes or side trails, you might gain 600m during the day, but return to your lodge 300m below. Your body begins to adapt without being overwhelmed overnight.
3. Hydrate, Hydrate, Hydrate
Dehydration makes AMS symptoms worse and slows your body’s ability to adapt. Aim for at least 3–4 liters of fluid per day, including herbal teas and soups.
Watch out for dehydration triggers:
- Cold weather reducing thirst cues
- Caffeine and alcohol (limit or avoid)
- Dry air at higher altitudes
4. Eat Well and Often
Your body burns more calories at altitude. Small, frequent meals high in carbs (rice, potatoes, bread, pasta) can help fuel the acclimatization process. Avoid heavy, greasy meals late at night, and listen to your appetite — it may decrease at higher altitudes.
5. Avoid Alcohol and Sleeping Pills
Both can suppress breathing and make it harder for your body to adapt. It might be tempting to toast a successful day with a beer, but it’s smarter to wait until you’re back at lower altitudes. Your lungs will thank you.
6. Know When to Rest
Don’t wait until you’re completely wiped out. If you feel even slightly off — headache, nausea, breathlessness — it’s okay to pause. Resting for a day often allows your body to catch up and symptoms to disappear.
7. Consider Acetazolamide (Diamox) — But Use With Care
Diamox is a medication that can help prevent or reduce the symptoms of AMS by encouraging faster breathing and improved oxygenation. Some trekkers take a low dose prophylactically before major altitude gains.
Important: Always consult your doctor before using Diamox. It’s not suitable for everyone and can have side effects. It’s also not a replacement for proper acclimatization.
8. Communicate With Your Guide
Altitude sickness isn’t something to tough out silently. If you’re feeling off, let your guide know. Resurgence Travel guides are trained to recognize AMS symptoms early and can adjust the pace or route as needed.
In fact, this is one of the greatest benefits of traveling with an experienced team — we’re not just there to lead, we’re there to protect your wellbeing.
Prevention is all about awareness and respect for the mountains. You don’t need to fear altitude — just understand it, work with it, and never be afraid to slow down. That’s how the Himalayas are meant to be experienced.
In the next section, we’ll talk about what to do if you do start experiencing symptoms — and how to respond in a way that keeps your trek on track and your health intact.
6. What to Do If You Experience Symptoms
Even with the best planning and preparation, altitude sickness can still happen. If it does, the most important thing is to recognize it early and take action calmly. AMS isn’t something to panic about — it’s your body’s way of asking for a break. And when you respond properly, most cases resolve quickly and without complication.
Step 1: Stop and Rest
If you start experiencing symptoms like headache, nausea, or dizziness, the first thing to do is stop and rest. Do not continue ascending. Even if the group is moving ahead or you feel the pressure to keep going — pause. One of the most dangerous mistakes trekkers make is “pushing through” early symptoms, which can allow mild AMS to develop into something more serious.
Rest for a few hours. Drink fluids. Eat something light. Often, this alone is enough for your body to recover.
Step 2: Tell Your Guide
Always notify your trekking guide or trip leader if you’re feeling off — even slightly. Resurgence Travel guides are trained to assess symptoms, adjust pacing, and support your recovery. They’ve seen this many times before and will never judge or dismiss your concerns.
Communication is key. The earlier you speak up, the easier it is to prevent escalation.
Step 3: Monitor Symptoms
If your symptoms improve after rest and hydration, it may be okay to stay at your current altitude overnight and reassess in the morning. But if symptoms persist or worsen, the safest option is always to descend.
Here’s a simple rule we use:
- Mild AMS (headache, slight fatigue): Stop and rest. Monitor closely. Delay ascent.
- Moderate AMS (persistent headache, nausea, breathlessness at rest): Descend immediately by 500–1,000m.
- Severe AMS / Signs of HAPE or HACE: Immediate descent and emergency medical attention required.
Never attempt to “sleep it off” at a high elevation if symptoms are getting worse. AMS doesn’t go away by pushing through — but it does improve quickly when you descend.
Step 4: Use Medications as Advised
If you’ve brought acetazolamide (Diamox) and have previously discussed its use with your doctor, it may help reduce symptoms or prevent them from worsening. Painkillers like ibuprofen or paracetamol can also help with altitude-related headaches — but remember, these treat the symptom, not the cause.
Medicines can be useful tools, but they’re not a substitute for proper decision-making. If you feel unwell, rest and descend are always the safest calls.
Step 5: Follow the Mountain Rule — The Mountain Will Always Be There
It’s easy to get caught up in reaching the next stop, the next peak, or that photo-perfect moment. But it’s far more important to return home healthy and proud of how you listened to your body. You can always come back. The mountain isn’t going anywhere.
At Resurgence Travel, our guides are trained not just to lead you, but to protect you. We carry pulse oximeters, first aid kits, and have emergency protocols in place — including access to helicopter rescue if necessary. But the best medicine is still prevention, and the best decisions are made with patience and humility.
Next, we’ll take a break from the technical side of things and share a personal account from someone who knows this challenge firsthand. Sonia’s story is a real-life look at what altitude sickness feels like — and how the right support can turn a difficult moment into a safe and successful journey.
7. Sonia’s Story: A Real Trekker’s Experience with Altitude Sickness
“I didn’t expect to feel weak. I’d trained so hard for this — and yet, there I was, halfway up a Himalayan slope, riding a horse instead of walking.”
I’ve always been someone who likes to be prepared. When I decided to trek in Nepal, I made a plan and stuck to it. Months of long walks, strength training, stretching, and staying consistent with my health — all so I could enjoy every single step of the trail when I finally got here.
And for the first couple of days, I really did. We landed in Lukla — the infamous little airstrip clinging to the mountains — and it was surreal. Just getting off the plane felt like stepping into a different world. The air was cool and thin, the sky impossibly wide. I was buzzing.
Our itinerary included acclimatization time, and I felt strong. A little breathless on climbs, but nothing I wasn’t ready for.
Then came day three.
It started with a slight headache. Nothing major. I just figured I hadn’t drunk enough water or maybe hadn’t slept that well. But by lunchtime, I was feeling slower. Everything felt a little heavier. I was still smiling — I’m always smiling — but I knew something wasn’t quite right.
By late afternoon, I was lightheaded, and my legs didn’t want to cooperate the way they usually do. I told my guide I was okay, just tired. He gave me a look. Not a worried look — just the kind that says, “We’ve seen this before.”
The next day, after checking in with him and the team, we decided I’d ride a horse part of the way. I won’t lie — that moment stung. I felt… embarrassed. I’ve never liked being the one who slows people down or needs extra help. I’m the one who carries snacks for everyone else, who cracks the jokes, who powers through.
But altitude doesn’t care who you are or how well you trained. And maybe that’s okay. Maybe it was good for me — to pause, to accept support, to remember that strength doesn’t always mean pushing through. Sometimes it means listening to your body and adjusting with grace.
The views were still spectacular. The team was endlessly kind. And the horse? A little grumpy, but solid as a rock.
I’m still on the trail as I write this, recovering well, going slow, and soaking in the journey from a slightly different perspective. And if you’re reading this because you’re worried about altitude sickness, here’s what I’ll say:
It’s okay to be human in the mountains. They’ll still let you in.
8. Final Thoughts
Trekking in Nepal is one of the most awe-inspiring, soul-stirring adventures a person can take. The mountains are majestic, the culture is rich, and the experience often becomes something far more meaningful than just reaching a destination.
But as you’ve seen in this guide, it’s not just about gear or grit — it’s about understanding your body, respecting the altitude, and being willing to listen when it whispers “slow down.”
Altitude sickness can affect anyone. It doesn’t mean you’ve failed. It means you’re human. And with the right knowledge, pacing, and support, you can still have the experience of a lifetime — safely and confidently.
At Resurgence Travel, we don’t just take you to Nepal’s most iconic places — we walk beside you, step by step. Our itineraries are crafted with altitude safety in mind, and our guides are trained to notice the little things, because they make the biggest difference.
If you’re planning your first trek — or your next one — and want to do it with a team that puts your safety and experience first, we’d love to help you get there. Let’s take the journey together.
Contact us today to learn more about our guided treks in Nepal and how we can help you prepare for altitude, adventure, and everything in between.
The mountains are calling — and now, you’re ready.
