Mount Everest Base Camp Elevation and Altitude Sickness

Everest Base Camp elevation is 5,364 metres (17,598 feet) above sea level, on the Nepal side of Mount Everest. At that altitude, atmospheric oxygen is close to half of what it is at sea level, and roughly 40 to 50 percent of trekkers on the EBC route experience some form of altitude sickness. The highest point of the standard trek is not Base Camp itself but Kala Patthar at 5,545 metres (18,192 feet), reached the morning after arrival at EBC for the sunrise view of Everest.

This guide covers the elevation numbers you need to plan for, what altitude sickness actually feels like at 5,364 metres, the three severity levels every trekker should recognize, and the acclimatization schedule we use on every one of our EBC treks.

How High Is Everest Base Camp?

Everest has two base camps because it has two standard climbing routes. Trekkers usually mean the Nepal side, the South Base Camp, when they say EBC.

South Base Camp (Nepal): 5,364 metres / 17,598 feet North Base Camp (Tibet): 5,150 metres / 16,900 feet

The South Base Camp is the one that appears in almost every EBC trek itinerary. It sits at the foot of the Khumbu Icefall in the Sagarmatha National Park, a UNESCO World Heritage Site. The North Base Camp, accessed via a jeep road from the Tibetan plateau, involves no trekking of comparable length and is a different experience entirely.

The Everest Base Camp elevation places it in what mountaineering medicine calls the "very high altitude" band (3,500 to 5,500 metres). Above 5,500 metres begins "extreme altitude," where the body can no longer acclimatize and slowly deteriorates. Base Camp itself is used by climbing expeditions for weeks at a time, but trekkers typically spend only a few hours there before descending.

For context on how thin the air is at this elevation: barometric pressure at 5,364 metres is roughly 505 millibars, compared to 1,013 millibars at sea level. Partial pressure of oxygen is proportionally reduced, which is why even fit, healthy trekkers move slowly and sleep poorly at this height.

Everest Base Camp Elevation vs Kala Patthar and Other High Points

A common confusion is that Base Camp is the highest point of the trek. It is not.

Kala Patthar, the small peak on the ridge above Gorak Shep, is 181 metres higher than Base Camp. Most trekkers climb Kala Patthar at dawn on the morning after their EBC visit, because from Base Camp itself the summit of Everest is not visible. From Kala Patthar, it is.

The elevation gain per day matters more than the absolute number. This is what actually determines whether a trekker feels well or gets sick.

Day-by-Day Altitude Gain on the 14 Days EBC Trek

The table below shows sleeping altitudes on the standard 14-day EBC itinerary, with the daily gain highlighted. Sleeping altitude is what your body has to adapt to overnight, and it is the number altitude physicians watch.

Two rules to notice in this schedule. First, the two acclimatization days at Namche and Dingboche are non-negotiable. They exist because both sit right at the altitude thresholds where AMS incidence spikes. Second, the day you touch Base Camp, you sleep 200 metres lower at Gorak Shep. You do not sleep at 5,364 metres. Sleeping altitude matters more than peak altitude, and this schedule respects that.

What Altitude Sickness Feels Like at 5,364 Metres

Almost every trekker feels something by the time they reach Dingboche (4,410 m). The question is how bad, and whether it is getting worse or better.

Mild AMS typically starts as a headache above 3,000 metres that will not respond to hydration or a nap. It is often accompanied by loss of appetite, mild nausea, disturbed sleep, and vivid or unpleasant dreams. Fatigue is out of proportion to the day's effort. Many trekkers describe it as feeling hungover without having drunk anything.

At the Everest Base Camp elevation of 5,364 metres, even fit trekkers walk at a fraction of their sea-level pace. Breathing at rest is faster and shallower. Climbing the final rise to Kala Patthar takes twice as long as the map suggests. Cognitive performance drops: simple decisions feel harder, and reaction time slows. This is normal and, on its own, not dangerous.

What is dangerous is when symptoms progress instead of stabilize, or when new symptoms appear. A trekker who has a headache at dinner in Lobuche and wakes with the same headache plus vomiting at Gorak Shep is not acclimatizing. They are getting sicker.

The Three Forms of Altitude Sickness: AMS, HAPE, HACE

Altitude illness exists on a spectrum. AMS is the mild and common form. HAPE and HACE are the severe, life-threatening forms. Recognizing the transition between them is the single most important skill on this trek.

Severity table

Acute Mountain Sickness (AMS)

AMS is the body's incomplete adjustment to reduced oxygen. It typically appears within 6 to 24 hours of arriving at a new altitude and resolves within one to three days if no further ascent is made. The Lake Louise Score, used in mountain medicine, defines AMS as a headache plus at least one other symptom (nausea, fatigue, dizziness, or sleep disturbance) at altitude.

Roughly 40 to 50 percent of EBC trekkers experience mild AMS at some point on the trek. It is normal. It is not dangerous on its own. What matters is not continuing to ascend while symptomatic.

High Altitude Pulmonary Edema (HAPE)

HAPE is fluid accumulation in the lungs, caused by pulmonary artery constriction at altitude. It typically develops on the second to fourth night at a new high altitude. Incidence on the EBC trek is roughly 0.5 to 2 percent.

The signature symptom is breathlessness at rest that is out of proportion to the altitude, together with a wet, unproductive cough. As it progresses, the cough produces pink or frothy sputum, the lips turn blue, and the person becomes exhausted from the effort of breathing.

HAPE kills faster than HACE. Descent of even 500 to 1,000 metres often produces dramatic improvement within hours. Delay does not.

High Altitude Cerebral Edema (HACE)

HACE is fluid on the brain, a rare (roughly 0.5 to 1 percent of EBC trekkers) but rapidly fatal form of altitude illness. It typically develops from untreated AMS that continues to ascend.

The classical HACE test is heel-to-toe walking in a straight line. A trekker who cannot do this reliably (called ataxia) has HACE until proven otherwise. Confusion, drowsiness, and altered consciousness follow. Untreated HACE can progress to coma and death within 24 hours.

Descent, dexamethasone, and supplemental oxygen are the three treatments. Descent is by far the most important.

How to Prevent Altitude Sickness on the EBC Trek

Prevention rests on four principles. In our 15 years of guiding EBC, trekkers who follow all four rarely have serious altitude problems. Trekkers who ignore even one of them account for the large majority of turned-back cases.

1. Ascend gradually. Above 3,000 metres, do not increase sleeping altitude by more than about 500 metres per day. Take a rest day for every 1,000 metres of gain above that threshold. The 14-day itinerary above follows this rule; shorter itineraries do not.

2. Climb high, sleep low. On the two acclimatization days at Namche and Dingboche, do not sit in the teahouse. Hike up to a higher point (Everest View Hotel from Namche, Nangkartshang from Dingboche) and return to sleep at the lower elevation. This is the single most effective acclimatization technique known.

3. Hydrate and eat. Dehydration mimics and worsens AMS. Aim for 3 to 4 litres of fluid per day above 3,000 metres. Loss of appetite is normal, but eat anyway. Carbohydrate-heavy meals are easier to tolerate than fat or protein at altitude.

4. Avoid alcohol and sleeping pills. Both suppress breathing during sleep, which is exactly the wrong effect at altitude. A single beer at Namche will not end your trek, but drinking above Dingboche is a bad idea.

Two more items to add to the list, both often overlooked:

• Slow pace. Walk more slowly than you think you need to. If you can hold a full conversation while walking, you are at the right pace. If you cannot, slow down.
• Recognize symptoms early. Tell your guide. Guides on the EBC trek have seen hundreds of cases and can catch progression that the trekker themselves cannot judge.

Diamox and Other Medications

Diamox (acetazolamide) is the most commonly used altitude sickness prophylaxis. It works by making the blood slightly acidic, which stimulates faster breathing and speeds acclimatization.

The Wilderness Medical Society (2019 consensus guidelines, the current version at time of writing) recommends 125 mg twice daily, starting the day before ascent above 3,000 metres and continuing until two to three days after reaching maximum altitude. Higher doses (250 mg twice daily) offer no additional benefit and increase side effects.

Common side effects include:

• Tingling in the fingers, toes, and lips (harmless)
• Increased urination
• Metallic taste, particularly of carbonated drinks
• Mild nausea

Diamox is a sulfa drug. Anyone with a sulfa allergy must not take it. It also interacts with certain medications, including some diabetes and blood pressure medicines. Consult your own doctor before your trek, ideally at least two weeks before departure, both to discuss suitability and to trial a dose at home.

Other medications commonly carried on the EBC trek by guides:

• Dexamethasone (8 mg initial dose, then 4 mg every 6 hours) for severe AMS or HACE, as a bridge to descent
• Nifedipine (30 mg extended-release) for HAPE, as a bridge to descent
• Ibuprofen or paracetamol for altitude headache

None of these are substitutes for descent. They are used to make descent possible.

Who Should Not Attempt the EBC Trek

Honesty is important here, because altitude does not care how badly you want to reach Base Camp.

Absolute contraindications:

• Pulmonary hypertension
• Sickle cell disease
• Recent stroke or TIA (within 3 months)
• Advanced COPD or severe asthma
• Recent cardiac event or unstable angina

Relative contraindications requiring medical clearance:

• Coronary artery disease
• Heart failure
• Well-controlled asthma
• Diabetes (both types), especially if using insulin
• Pregnancy (the CDC advises against sleeping above 3,600 metres during pregnancy)
• Any condition requiring medication that interacts with altitude physiology

Age itself is not a contraindication. We have guided trekkers in their 70s successfully to Base Camp. Fitness itself is not protective against AMS, either. Marathon runners and Olympic athletes get altitude sickness at the same rate as sedentary trekkers; the only difference is how quickly they can walk out.

If you have any condition on either list above, get a medical clearance from a physician familiar with altitude medicine before booking. Not a general practitioner unfamiliar with the topic.

Insurance and Helicopter Evacuation

Trekking insurance for the EBC route is not optional and not the same as standard travel insurance.

A helicopter evacuation from Gorak Shep or EBC currently costs USD 4,000 to 8,000, paid up front before the aircraft launches. Without insurance, or with the wrong insurance, that is a real problem for a sick trekker at 5,164 metres.

Your policy must explicitly cover:

• Helicopter evacuation at altitudes up to at least 6,000 metres
• Medical treatment in Kathmandu (Norvic, CIWEC, or Grande hospitals)
• Repatriation home if required
• The specific activity of "trekking above 3,000 metres" or similar language

Ordinary travel insurance and most credit-card travel insurance excludes high-altitude trekking. Specialist providers used regularly by EBC trekkers include World Nomads, Global Rescue, IMG Signature Travel, and, for UK trekkers, the BMC (British Mountaineering Council) policy. Verify current coverage terms with the provider before purchase.

Bring both digital and paper copies of the policy on the trek. Your guide will need the policy number and the insurer's 24-hour rescue number to initiate an evacuation.

When to Descend: The Emergency Rule

The rule taught in every altitude medicine course, and worth memorizing, is:

Descent is the only definitive treatment for HAPE and HACE. Every hour of delay makes the outcome worse. Cost, disappointment, group pressure, and "I can push through this" reasoning are how altitude fatalities happen on this trek.

A trekker who descends 500 to 1,000 metres and improves has had a scare. A trekker who tries to push through the night at altitude with worsening symptoms is gambling with their life.

There is no shame in turning back from EBC. There is a real cost to trying to force the summit of Kala Patthar when the body has said no. Guides on this trek make hard calls, and trekkers who trust their guide's judgment finish the trek healthy far more often than those who override it.

Frequently Asked Questions

What altitude is Everest Base Camp?

verest Base Camp on the Nepal side sits at 5,364 metres (17,598 feet) above sea level. The Tibetan (north) side base camp is slightly lower at 5,150 metres (16,900 feet).

How high is Everest Base Camp compared to Kala Patthar?

Kala Patthar, at 5,545 metres (18,192 feet), is 181 metres higher than Everest Base Camp. Most trekkers hike up Kala Patthar the morning after reaching Base Camp because it offers a better view of Everest's summit.

Can you get altitude sickness at Everest Base Camp?

Yes. At 5,364 metres, oxygen levels are roughly half of what they are at sea level. Studies of trekkers on the EBC route show that 40 to 50 percent experience some form of acute mountain sickness. A smaller share develop the two severe forms, HAPE and HACE, which are life-threatening if the person does not descend.

How common is altitude sickness on the EBC trek?

Research published by the Wilderness Medical Society and epidemiological studies of Himalayan trekkers place the incidence of mild AMS on the EBC trek at around 40 to 50 percent. Severe forms such as HAPE and HACE occur in roughly 1 to 2 percent of trekkers at these altitudes.

How do you prevent altitude sickness on the EBC trek?

Prevention rests on four principles: gradual ascent (no more than about 500 metres of sleeping altitude gained per day above 3,000 metres), scheduled rest days at Namche and Dingboche, staying well hydrated, and considering Diamox after consulting a doctor. Alcohol and sleeping medications should be avoided.

Do I need Diamox for Everest Base Camp?

Diamox is not mandatory, but it is widely used as a preventive measure on the EBC trek. The Wilderness Medical Society recommends 125 mg twice daily, started the day before ascent above 3,000 metres and continued for two to three days after reaching maximum altitude. Consult your doctor before your trek, as Diamox interacts with certain medications and is contraindicated for people with sulfa allergies.

What is the difference between AMS, HAPE, and HACE?

AMS (Acute Mountain Sickness) is the mildest form, presenting with headache, nausea, fatigue, and poor sleep. HAPE (High Altitude Pulmonary Edema) is fluid in the lungs and produces breathlessness at rest, wet cough, and pink or frothy sputum. HACE (High Altitude Cerebral Edema) is fluid on the brain and causes confusion, loss of coordination, and altered consciousness. HAPE and HACE are medical emergencies that require immediate descent.

What insurance do I need for the EBC trek?

Trekking insurance for Everest Base Camp must cover helicopter evacuation up to at least 6,000 metres. Emergency helicopter rescue from EBC typically costs between USD 4,000 and USD 8,000. Standard travel insurance rarely includes high-altitude evacuation; a specialist adventure travel policy is required.

Is fitness enough to prevent altitude sickness?

No, fit trekkers get altitude sickness at the same rate as unfit trekkers. The only advantage fitness confers is a faster descent if things go wrong.