Using a Pulse Oximeter for Altitude Monitoring on Nepal Treks: Complete SpO2 Guide
A small, inexpensive device clipped to your fingertip might be one of the most valuable pieces of gear in your trek pack -- or it might become a source of needless anxiety that ruins your trip. The pulse oximeter (also called an SpO2 monitor) has become increasingly popular among trekkers heading to high altitude in Nepal, and for good reason: it provides an objective measurement of how well your body is handling altitude. But like any tool, its value depends entirely on understanding what it tells you, what it does not tell you, and how to use the information wisely.
This guide covers everything a Nepal trekker needs to know about pulse oximeters: what they measure and why it matters, normal SpO2 readings at different altitudes, how to take accurate readings, when a low reading means trouble versus when it is perfectly normal, device recommendations, limitations you must understand, and most importantly, how to combine SpO2 data with symptom monitoring for sound decision-making at altitude.
95-100%
88-92%
80-88%
Below 80% at any altitude
$15-$50 USD
30-50 grams
20-40 hours typical use
Cold fingers give false low readings
What a Pulse Oximeter Measures
A pulse oximeter measures two things:
1. Blood Oxygen Saturation (SpO2)
This is the percentage of hemoglobin molecules in your arterial blood that are carrying oxygen. At sea level, healthy individuals typically show 95-100%. At altitude, this number drops because there is less oxygen in the thinner air. Your body compensates through various acclimatization mechanisms (increased breathing rate, increased heart rate, increased red blood cell production), but SpO2 will always be lower at altitude than at sea level.
2. Pulse Rate (Heart Rate)
The device also displays your heart rate in beats per minute. An elevated resting heart rate at altitude is normal (your heart beats faster to circulate available oxygen more quickly), but an extremely elevated or irregular heart rate can be a warning sign.
How It Works
The device shines two wavelengths of light (red and infrared) through your fingertip. Oxygenated hemoglobin absorbs different amounts of light than deoxygenated hemoglobin. By measuring the difference, the device calculates what percentage of your hemoglobin is carrying oxygen. The measurement is painless, non-invasive, and takes about 10-15 seconds for a stable reading.
Normal SpO2 Readings at Different Altitudes
This is the information most trekkers are looking for. Understanding what is "normal" at each altitude prevents both false alarm and dangerous complacency.
SpO2 Ranges by Altitude
| Altitude | Location Example | Typical SpO2 Range (Acclimatized) | Concern If Below | |----------|-----------------|-----------------------------------|------------------| | Sea level | Home (most trekkers) | 95-100% | 94% | | 1,400m | Kathmandu | 93-98% | 92% | | 2,860m | Lukla | 90-95% | 88% | | 3,440m | Namche Bazaar | 88-93% | 85% | | 3,800m | Tengboche | 86-92% | 83% | | 4,350m | Dingboche | 83-90% | 80% | | 4,930m | Lobuche | 80-87% | 77% | | 5,164m | Gorak Shep | 78-85% | 75% | | 5,364m | Everest Base Camp | 75-84% | 73% | | 5,416m | Thorong La Pass | 74-83% | 72% | | 5,644m | Kala Patthar | 72-82% | 70% |
Important notes about this table:
- These are typical ranges for well-acclimatized trekkers following standard itineraries
- Individual variation is significant -- some healthy people naturally read 3-5% lower than average
- Readings during the first night at a new altitude are typically lower than after acclimatization
- Morning readings are usually lower than afternoon readings
- These ranges assume proper acclimatization schedules with appropriate rest days
Do Not Treat SpO2 Numbers in Isolation
A single SpO2 reading, by itself, should never be the sole basis for a descent decision. SpO2 must always be interpreted in context: the altitude, the individual's baseline, their symptoms, the trend over time, and the conditions of measurement. A trekker reading 82% at 5,000m who feels great and has been acclimatizing normally is in a completely different situation from a trekker reading 82% at 3,500m who has a pounding headache and is vomiting.
Understanding Individual Variation
One of the most important things to understand about SpO2 at altitude is that there is enormous individual variation. Some people naturally maintain higher saturations at altitude, and some people naturally run lower -- without either being in danger.
Factors affecting individual SpO2 baseline:
- Genetics: Populations with generations of high-altitude ancestry (Sherpas, Tibetans) often show higher SpO2 at altitude
- Fitness level: Generally fit individuals may have slightly higher SpO2, but fitness does not guarantee high readings
- Acclimatization history: People who have recently been to altitude may acclimatize faster
- Age: Older trekkers may have slightly lower baselines
- Underlying health conditions: Lung conditions, heart conditions, and anemia affect SpO2
- Smoking status: Smokers may have lower baseline SpO2
This is why establishing your personal baseline is more valuable than comparing your numbers to a chart or to other trekkers.
Pro Tip
Establish your personal baseline before the trek. Take SpO2 readings at home (sea level) for several days to know your normal. Then take readings at each altitude during your trek. What matters most is not the absolute number but the trend and how your reading compares to YOUR baseline. If you normally read 98% at sea level and you are reading 82% at 4,500m, that is an 16-point drop. If your trekking partner normally reads 96% and is reading 80% at the same altitude, that is also a 16-point drop -- even though their absolute number is lower, their relative acclimatization is similar.
How to Take Accurate Readings
A pulse oximeter is only useful if the reading is accurate. Several factors common at altitude can produce false readings.
Getting an Accurate Reading
- Warm your hands first. Cold fingers are the number one cause of falsely low readings at altitude. Tuck your hands in your armpits or pockets for 2-3 minutes before measuring. Rub your hands together. The fingertip must have good blood flow for an accurate reading
- Sit down and rest for 5 minutes before measuring. Readings taken immediately after exertion are lower and less meaningful
- Remove nail polish or artificial nails from the finger you are measuring. These can interfere with the light sensor
- Hold your hand steady at heart level. Do not wave it around or hold it above your head
- Wait for a stable reading. The number will fluctuate for the first 5-10 seconds. Wait until it stabilizes (the number holds steady for at least 5 seconds)
- Try multiple fingers if a reading seems unusually low. If one finger reads 75% and others read 84%, the 75% reading was likely inaccurate
- Check the pulse wave indicator. Most pulse oximeters display a signal quality indicator (bar graph or wave). If the signal is weak or erratic, the reading is unreliable
- Take readings at the same time each day for meaningful trend comparison (morning resting readings are most consistent)
Common Causes of False Readings
| Cause | Effect on Reading | Solution | |-------|-------------------|----------| | Cold fingers | Falsely low SpO2 | Warm hands thoroughly before measuring | | Nail polish (dark colors) | Falsely low SpO2 | Remove polish or measure a different finger | | Bright ambient light | Variable, often falsely high | Cup your other hand over the device to shade it | | Movement or shivering | Erratic, unreliable readings | Sit still, warm up, wait for stable conditions | | Poor circulation | Falsely low SpO2, weak signal | Warm hands, try a different finger, dangle hand | | Dark skin pigmentation | May read slightly lower | Use the same finger consistently for trend tracking | | Low battery | Erratic readings | Replace battery (carry spares) | | Altitude itself | Longer stabilization time | Wait longer for stable reading (15-20 seconds) |
The Cold Finger Problem at Altitude
Cold fingers are the most common reason for misleadingly low SpO2 readings on Nepal treks, and they cause more unnecessary panic than perhaps any other factor. At 5,000m on a cold morning, your fingers may be genuinely cold despite wearing gloves. A reading taken with cold fingers might show 70% when your actual saturation is 82%. Always warm your hands thoroughly before measuring. If in doubt about a reading, warm your hands more aggressively and try again. If the second reading is significantly higher, the first was likely a cold-finger artifact.
The Decision Framework: When SpO2 Plus Symptoms Equal Action
The real value of a pulse oximeter is not in any single number -- it is in combining SpO2 data with symptom monitoring to make better decisions. Here is a practical decision framework for Nepal trekkers.
The Traffic Light System
GREEN: Continue Trekking Normally
- SpO2 is within expected range for your altitude (see table above)
- No symptoms or only very mild headache that resolves with hydration and ibuprofen
- SpO2 is stable or improving compared to your previous readings at this altitude
- Resting heart rate is elevated but stable (not racing)
YELLOW: Proceed with Caution
- SpO2 is at the lower end of the expected range or slightly below the "concern" threshold
- Mild AMS symptoms present (headache, mild nausea, fatigue, poor sleep)
- SpO2 has dropped compared to the same time yesterday at the same altitude
- Heart rate is significantly elevated above your usual altitude-adjusted rate
- Action: Do not ascend further today. Take a rest day. Monitor symptoms and SpO2. Increase hydration and food intake. If symptoms do not improve in 24 hours, descend
RED: Descend Immediately
- SpO2 is well below 80% at any altitude (after confirming with warm fingers and multiple readings)
- SpO2 is dropping over time despite rest at the same altitude
- Any symptoms of HACE (confusion, inability to walk straight, severe headache unresponsive to medication)
- Any symptoms of HAPE (breathlessness at rest, gurgling sounds when breathing, cough with pink or frothy sputum)
- SpO2 below 70% at any altitude regardless of symptoms
- Action: Descend immediately. Do not wait for morning. Administer Diamox, dexamethasone, or nifedipine if available and indicated. Consider helicopter evacuation if descent on foot is not possible
Detailed Decision Table
| SpO2 Reading | Symptoms | Altitude Context | Action | |-------------|----------|-----------------|--------| | Above 85% | None | Any altitude up to 5,500m | Continue normally | | 80-85% | None | Above 4,500m | Normal; continue with awareness | | 80-85% | Mild headache, fatigue | Above 4,500m | Monitor closely; rest day recommended | | 80-85% | None | Below 4,000m | Lower than expected; investigate cause (cold fingers? dehydration?) | | 75-80% | None | Above 5,000m | Monitor closely; ensure proper acclimatization | | 75-80% | Headache, nausea, poor sleep | Above 4,500m | Do not ascend; rest day; descend if no improvement | | 75-80% | Any symptoms | Below 4,500m | Concerning; strong indication to descend | | Below 75% | None | Above 5,000m | Verify reading; if confirmed, consider descent | | Below 75% | Any AMS symptoms | Any altitude | Descend | | Below 70% | Any | Any altitude | Descend immediately |
Pro Tip
Track your SpO2 trend, not just snapshots. Take readings twice daily (morning resting and evening resting) and record them in your trek journal alongside your altitude and any symptoms. Over the course of your trek, you will see a pattern: SpO2 drops when you gain altitude, then partially recovers during rest days as you acclimatize. A normal pattern is "drop on ascent days, partial recovery on rest days." A concerning pattern is "dropping on rest days" or "not recovering between ascent days" -- these suggest your body is not acclimatizing adequately.
Don't Obsess Over the Numbers
This section is as important as any technical guidance in this article. The pulse oximeter is a tool to inform decisions, not a source of anxiety.
The Obsession Problem
Every trek season, Himalayan Rescue Association doctors encounter trekkers who are so fixated on their SpO2 numbers that it dominates their trekking experience. They check obsessively -- morning, afternoon, before meals, after meals, during the night. Every one-point drop triggers panic. They compare numbers with other trekkers and feel anxious when their reading is lower. They lose sleep worrying about their numbers rather than their actual wellbeing.
This number obsession is counterproductive for several reasons:
- Anxiety increases heart rate and alters breathing patterns, which can actually lower SpO2 readings, creating a self-fulfilling worry cycle
- SpO2 fluctuates normally throughout the day and between measurements. Checking every 30 minutes guarantees you will see numbers that frighten you
- SpO2 is a supplementary tool, not a replacement for symptom awareness. How you feel is more important than what the number says
- Comparing with other trekkers is meaningless due to individual variation
Healthy Pulse Oximeter Habits
- Check twice daily -- morning resting and evening resting. That is enough
- Record the numbers in your trek journal for trend tracking
- If you feel fine, trust your body. A low number in an asymptomatic trekker is far less concerning than a normal number in a trekker with severe headache
- If you feel awful, the number does not matter. Symptoms warrant rest or descent regardless of what the oximeter says
- Do not check in the middle of the night. Nighttime readings are often lower (normal), and a low reading at 2:00 AM will destroy your sleep without being actionable
- Share your readings with your guide, not as a basis for panic, but as data they can help you interpret
Symptoms Always Trump Numbers
If a trekker feels terrible -- persistent headache, nausea, vomiting, dizziness, confusion, breathlessness -- they should rest or descend regardless of what the pulse oximeter shows. Altitude sickness is a clinical diagnosis based on symptoms, not on SpO2 readings. The oximeter is a supplementary tool that provides additional data. It does not replace the question "How do I feel?"
Device Recommendations
What to Look for in a Trekking Pulse Oximeter
| Feature | Importance | Notes | |---------|------------|-------| | Fingertip style | Essential | Clip-on fingertip models are the most practical for trekking | | SpO2 and pulse display | Essential | Both readings visible simultaneously | | Signal quality indicator | Highly recommended | Shows whether the reading is reliable | | Long battery life | Important | 20+ hours; uses AAA or CR2032 batteries | | Small and lightweight | Important | Under 50g; fits in jacket pocket | | Durability | Important | Will be bumped around in a backpack | | Low perfusion accuracy | Nice to have | Better accuracy with cold fingers | | Altitude-rated | Nice to have | Some are specifically designed for altitude use | | Bluetooth/app connectivity | Optional | Track readings digitally (nice but not necessary) |
Recommended Devices
Budget Option ($15-25): Standard fingertip pulse oximeters from brands like Zacurate, Innovo, or Santamedical. These work well for most trekkers and provide accurate readings when used correctly. Available on Amazon or in pharmacies.
Mid-Range Option ($25-40): Devices like the Masimo MightySat or Nonin GO2 offer better low-perfusion accuracy (important for cold-finger situations at altitude) and more reliable signal quality. Worth the extra cost for serious altitude trekkers.
High-End Option ($40-60+): Medical-grade devices like the Nonin Onyx Vantage 9590 offer the best accuracy in challenging conditions. Used by mountain medicine professionals and HRA clinics. If you are trekking to extreme altitude (above 5,500m) or have a health condition that makes monitoring important, this level of device is worth considering.
Smartphone-Based: Some smartphone apps claim to measure SpO2 using the phone's camera and flash. These are unreliable at altitude and should not be used for altitude monitoring. Use a dedicated device.
Pro Tip
Bring spare batteries. A pulse oximeter is useless with a dead battery, and batteries drain faster in cold temperatures. AAA batteries are available in Namche Bazaar and other major trail towns, but selection is limited and expensive. Bring two sets of spares from home or Kathmandu. If your device uses CR2032 coin cell batteries, these are harder to find on the trail -- definitely carry spares.
Pulse Oximetry and the Lake Louise AMS Scoring System
The most widely used system for assessing altitude sickness is the Lake Louise Acute Mountain Sickness (AMS) Score. A pulse oximeter reading can complement this system but does not replace it.
The Lake Louise System (Abbreviated)
The Lake Louise score assesses five symptoms on a scale of 0-3:
- Headache (0 = none, 1 = mild, 2 = moderate, 3 = severe)
- Gastrointestinal (0 = none, 1 = poor appetite/nausea, 2 = moderate nausea/vomiting, 3 = severe)
- Fatigue/weakness (0 = none, 1 = mild, 2 = moderate, 3 = severe/incapacitating)
- Dizziness/lightheadedness (0 = none, 1 = mild, 2 = moderate, 3 = severe)
- Sleep quality (0 = normal, 1 = not as well as usual, 2 = waking frequently, 3 = unable to sleep)
AMS diagnosis: Headache score of at least 1, plus a total score of 3 or more, at altitude above 2,500m.
Combining SpO2 with Lake Louise
| Lake Louise Score | SpO2 Reading | Interpretation | Action | |-------------------|-------------|----------------|--------| | 0-2 (no AMS) | Within expected range | Normal acclimatization | Continue | | 0-2 (no AMS) | Lower than expected | Monitor; possibly acclimatizing slowly | Extra rest day | | 3-5 (mild AMS) | Within expected range | Mild AMS; body is coping | Do not ascend; monitor | | 3-5 (mild AMS) | Lower than expected | Mild AMS with poor saturation | Do not ascend; rest day; consider descent | | 6+ (moderate/severe AMS) | Any reading | Significant altitude sickness | Descend | | Any score | Dropping trend over time | Acclimatization failing | Do not ascend; rest or descend |
For detailed altitude sickness information, see our altitude sickness prevention and treatment guide and our acclimatization guide.
Limitations of Pulse Oximeters
Understanding what a pulse oximeter cannot do is as important as understanding what it can do.
What Pulse Oximeters Do NOT Tell You
- They do not diagnose altitude sickness. AMS, HACE, and HAPE are clinical diagnoses based on symptoms. SpO2 is supplementary data
- They do not predict who will get altitude sickness. A good SpO2 reading today does not guarantee you will be fine tomorrow
- They do not measure oxygen in your lungs or tissues. They measure hemoglobin saturation in arterial blood only
- They do not account for carbon monoxide. In tea houses with poor ventilation and kerosene heaters, carbon monoxide can falsely elevate SpO2 readings (carbon monoxide binds to hemoglobin and is read as oxygen by most oximeters)
- They do not replace medical judgment. A doctor assessing a patient considers many factors beyond SpO2
Specific Limitations at Altitude
- Cold environments reduce accuracy (as discussed extensively above)
- Dehydration (common at altitude) can reduce peripheral perfusion and lower readings
- Irregular heart rhythms (which can occur at altitude) may cause erratic readings
- Dark skin pigmentation may cause slightly lower readings on some devices (this is a known limitation of the technology, and studies have shown it can be clinically significant)
- Motion during measurement produces unreliable results
- Very low saturations (below 70%) are inherently less accurate, as most consumer devices are calibrated for the 70-100% range
Carbon Monoxide Warning
Some tea houses at higher altitudes use kerosene or yak dung heaters in poorly ventilated rooms. Carbon monoxide from these heaters binds to hemoglobin just like oxygen does, and most pulse oximeters cannot distinguish between the two. This means your SpO2 reading could appear normal or even high while you are actually being poisoned by carbon monoxide. If you experience headache, dizziness, nausea, or confusion in a tea house with a heater running, open the windows and get fresh air immediately -- do not rely on a reassuring SpO2 reading.
SpO2 Monitoring on Specific Nepal Treks
Everest Base Camp Trek
The EBC trek is the most common context for pulse oximeter use, given its progressive altitude gain over 12-14 days.
Key monitoring points:
- Namche Bazaar (3,440m): Your first significant altitude. Expect SpO2 of 88-93% after your rest day
- Tengboche (3,867m): Readings of 86-92%. Compare with Namche readings to assess acclimatization
- Dingboche (4,358m): Critical monitoring point before the push higher. 83-90% is typical
- Lobuche (4,940m): 80-87%. If you are significantly below this despite warm fingers, the rest day at Dingboche may not have been enough
- Gorak Shep/EBC (5,164-5,364m): 75-85%. This is the highest point, and your lowest readings. If you feel well and are reading 78%, you are doing fine
Annapurna Circuit (Thorong La)
- Monitor closely at Manang (3,540m) during your rest days
- Take baseline readings before the Thorong La crossing
- After the pass (5,416m), readings will recover as you descend to Muktinath (3,800m)
Three Passes Trek (Everest Region)
This trek involves repeated altitude gains over three high passes (Kongma La 5,535m, Cho La 5,420m, Renjo La 5,360m). SpO2 monitoring is particularly valuable here because you repeatedly ascend and descend, and your readings should show a pattern of improved acclimatization with each pass.
Frequently Asked Questions
Is a pulse oximeter worth bringing on a Nepal trek?
Yes, for most trekkers heading above 4,000m, a pulse oximeter is a worthwhile addition to your kit. It weighs almost nothing (30-50g), costs very little ($15-40), and provides useful data for monitoring acclimatization. However, it is not essential -- millions of trekkers have safely completed high-altitude treks without one. It is a supplementary tool that adds value when used correctly, not a necessity.
What SpO2 reading should I worry about?
There is no single "worry" number because context matters enormously. As a general guideline: below 80% at any altitude warrants attention (verify the reading, check symptoms, rest). Below 75% at any altitude below 5,000m is concerning. Below 70% at any altitude, combined with symptoms, is an emergency. But always combine the number with how you feel. A reading of 78% in a symptom-free trekker at 5,300m is normal. The same reading at 3,500m with a headache is very concerning.
Why does my reading differ from my trekking partner's at the same altitude?
Individual variation is enormous and completely normal. Differences of 5-8% between individuals at the same altitude are common. Genetics, fitness, prior altitude exposure, age, and health all affect SpO2 at altitude. Do not compare your numbers with others -- compare your numbers with your own previous readings to track your personal acclimatization trend.
Can a pulse oximeter predict altitude sickness before symptoms appear?
Research suggests that SpO2 readings may drop before clinical symptoms of AMS develop, but the predictive value is not strong enough to be reliable for individuals. A dropping SpO2 trend over several readings may be an early warning, but some people have low SpO2 without ever developing AMS, and some develop AMS despite reasonable SpO2 readings. Symptom monitoring remains the primary tool.
Should I check my SpO2 during the night?
Generally, no. SpO2 naturally drops during sleep, especially at altitude, and periodic breathing (cycles of deep breathing followed by shallow breathing or brief pauses) is common and normal above 3,000m. A nighttime reading will often be lower than your daytime resting reading, and checking it at 2:00 AM will likely cause anxiety without providing actionable information. Stick to morning and evening resting readings for consistent trend data.
My reading is 78% and I feel completely fine at 5,000m. Should I be worried?
Probably not, as long as you have verified the reading (warm fingers, stable reading, tried multiple fingers). A reading of 78% at 5,000m is within the typical range for a well-acclimatized trekker. If you have no headache, no nausea, no unusual fatigue, and you are following a proper acclimatization schedule, a reading of 78% is not alarming. Continue to monitor and do not ascend if the reading drops further or symptoms develop.
Can I use my smartwatch SpO2 function instead of a dedicated oximeter?
Smartwatches and fitness trackers with SpO2 functions (Apple Watch, Garmin, Fitbit) provide general trend data but are less accurate than dedicated fingertip pulse oximeters, especially in the challenging conditions at altitude (cold, motion, poor perfusion). For casual monitoring, a smartwatch reading is reasonable. For clinical decision-making about whether to ascend or descend, a dedicated fingertip device is more reliable.
How does dehydration affect SpO2 readings?
Dehydration reduces blood volume and peripheral perfusion, which can cause pulse oximeters to give lower readings. This is particularly relevant at altitude, where dehydration is extremely common due to dry air, increased respiration, and insufficient fluid intake. Before concluding that a low SpO2 reading reflects poor acclimatization, drink 500ml of water and wait 30 minutes, then remeasure. If the reading improves significantly, dehydration was likely a factor.
Do Sherpas and local guides have higher SpO2 at altitude than foreign trekkers?
Generally, yes. Populations with generations of high-altitude ancestry, including Sherpas and Tibetans, have genetic adaptations that allow them to maintain higher blood oxygen saturation at altitude. Studies have shown that Sherpas at 5,000m often maintain SpO2 readings 3-8% higher than lowland-born trekkers at the same altitude. This is a genetic advantage related to hemoglobin affinity and vascular adaptations -- it is not something that training can replicate.
Can I use a pulse oximeter to decide if I should take Diamox?
A pulse oximeter reading alone should not determine whether you take Diamox. The decision to use Diamox (acetazolamide) should be based on your overall acclimatization plan, symptoms, and ideally consultation with a doctor or HRA clinic. However, if you are already planning to take Diamox prophylactically and are wondering if it is working, tracking SpO2 before and after starting Diamox can show whether it is improving your acclimatization. Many people show a 3-5% improvement in SpO2 after starting Diamox. See our Diamox guide for comprehensive information.
What if my pulse oximeter reads zero or shows an error?
If your device shows an error or no reading, the most likely causes are: dead battery, finger too cold, finger positioned incorrectly in the device, or the device is malfunctioning. Try warming your hands thoroughly, repositioning your finger (nail side up, fully inserted), and trying a different finger. If it still fails, check or replace the battery. If the device has been dropped or exposed to moisture, it may have malfunctioned -- this is why carrying a backup set of batteries and knowing how to interpret symptoms without the device is important.
Key Takeaways
A pulse oximeter is a valuable but imperfect tool for altitude monitoring on Nepal treks. Use it wisely:
- Establish your personal baseline before and during the trek
- Warm your hands before every measurement -- cold fingers ruin accuracy
- Track trends, not snapshots. Twice-daily readings recorded in your journal are more useful than obsessive checking
- Combine SpO2 with symptoms. Numbers plus how you feel equals informed decisions
- Do not obsess. The oximeter is a supplement, not a substitute for body awareness
- Below 80% deserves attention. Below 70% at any altitude is an emergency (after verifying the reading)
- Symptoms always trump numbers. If you feel terrible, act on how you feel regardless of what the device shows
For comprehensive altitude safety information, see our guides on altitude sickness prevention, acclimatization, and HAPE and HACE emergencies.
This guide provides general health information for educational purposes. It is not a substitute for medical advice. For concerns about altitude sickness or SpO2 readings during your trek, consult a medical professional or visit an HRA clinic (located at Pheriche and Manang).