Climbing Mount Everest is a two-month ordeal of waiting, suffering, and slow upward progress, punctuated by a single 12-hour push to the summit in the middle of the night. Most of that time isn’t spent climbing at all. It’s spent sitting in a tent at base camp, eating, hydrating, and letting your body slowly adapt to air that contains a fraction of the oxygen you’re used to breathing. The experience is less like scaling a dramatic peak and more like a grueling, expensive camping trip where the altitude tries to kill you in small increments.
The First Two Weeks: Getting to Base Camp
The expedition begins not with climbing but with walking. Most climbers fly into Lukla, a small airstrip carved into a mountainside in eastern Nepal, and then trek for 7 to 12 days through the Khumbu Valley to reach Everest Base Camp at 5,364 meters (17,598 feet). The pace is deliberately slow. You’re already gaining altitude, and your body needs time to start producing more red blood cells and adjusting to thinner air. By the time you arrive at base camp, you’ve been in Nepal for nearly two weeks and haven’t touched the mountain yet.
Base camp itself is a small city of tents spread across the Khumbu Glacier. There are dining tents, communication tents, and even a makeshift medical clinic. You’ll spend more time here than anywhere else on the expedition, and the monotony is a real part of the experience. Climbers read, play cards, call home on satellite phones, and eat meals prepared by camp cooks.
Acclimatization: Climbing Up to Come Back Down
The next four to six weeks are consumed by acclimatization rotations. This is the core rhythm of an Everest expedition: climb partway up the mountain, sleep at a higher camp for a night or two, then descend back to base camp to recover. Each rotation goes a little higher. First to Camp 1 at roughly 6,000 meters, then to Camp 2 at 6,400 meters, eventually touching Camp 3 near 7,200 meters before retreating again.
The purpose is to trick your body into adapting. At these altitudes, each breath delivers significantly less oxygen than at sea level. Your breathing rate increases, your heart works harder, and your body ramps up red blood cell production. Rushing this process causes altitude sickness, which can progress to fluid in the lungs or brain swelling, both potentially fatal. So you wait. You climb. You come back down. You wait again. The boredom and restlessness are constant companions.
Appetite drops sharply at altitude, even as your body burns far more calories than normal. Research on Everest expeditions found that climbers at base camp consumed around 2,800 calories per day, but actual energy expenditure at higher camps far exceeds that. The result is that nearly every climber loses significant weight over the course of the expedition. Meals at the higher camps are simple: instant noodles, freeze-dried food, energy bars, tea, and soup. At base camp, cooks prepare more substantial meals, but even there, many climbers struggle to eat enough.
What Extreme Altitude Does to Your Body
Above 8,000 meters (26,247 feet), you enter what climbers call the “death zone.” The name isn’t hyperbole. At this altitude, there is roughly one-third the oxygen available at sea level, and your body cannot sustain itself for long. Blood oxygen measurements taken from climbers at 8,400 meters on Everest, published in the New England Journal of Medicine, showed arterial oxygen levels so low that the pulse oximeters researchers carried couldn’t even register them accurately, as they weren’t calibrated below 70% saturation. For context, a healthy person at sea level sits around 95 to 100%.
The oxygen content in climbers’ blood at 8,400 meters was 26% lower than at 7,100 meters, despite the relatively small altitude gain. This is the zone where your body is actively deteriorating. Thinking becomes foggy. Simple tasks like clipping a carabiner or zipping a jacket take enormous concentration. Your muscles are starved of oxygen, so every step feels like wading through wet concrete. Most climbers use supplemental oxygen above Camp 3, breathing through a mask connected to bottles carried on their backs. Even with supplemental oxygen, the experience is exhausting in a way that’s hard to convey to someone who hasn’t felt it.
Summit Night
The summit push begins from Camp 4 on the South Col, at about 7,950 meters. You leave at roughly 10 p.m., stepping into total darkness with a headlamp and supplemental oxygen flowing through your mask. The temperature at the summit during the May climbing window averages around minus 26°C (minus 15°F), but winds averaging 16 meters per second (about 36 mph) push the wind chill down to around minus 45°C (minus 49°F). At those conditions, exposed skin can get frostbitten in as little as six minutes.
The climb to the summit takes about eight hours. You move in a line of climbers, clipped to a fixed rope, one slow step at a time. The famous features along the route, the Balcony, the South Summit, the Hillary Step, pass by in a haze of effort. Many climbers describe summit night as a state of pure mechanical determination: one foot, then the other, breathe, repeat. Conversation is nearly impossible. You can hear your own breathing amplified inside your oxygen mask and the wind tearing at your suit.
The summit itself is a small area, roughly the size of a dining table. Climbers typically spend only 10 to 15 minutes there before turning around, because every additional minute above 8,000 meters increases the danger. The descent to Camp 4 takes about four more hours, meaning the entire summit day is a 12-hour effort at the edge of what the human body can tolerate.
The Conditions You Live In
For weeks, your world shrinks to the inside of a tent. At the higher camps, tents are pitched on narrow ledges carved into snow and ice. Wind batters the fabric all night. Sleep above 6,000 meters is fitful at best. Many climbers wake repeatedly, gasping, as their breathing patterns become irregular at altitude (a condition called periodic breathing, where your body alternates between hyperventilating and barely breathing at all).
Personal hygiene essentially stops. You don’t shower for two months. You wear the same base layers for days. Since 2024, Nepal requires climbers to carry their own human waste down from the upper camps in specially designed bags that contain chemicals to solidify and deodorize it. Each climber receives two reusable bags for the roughly two weeks spent at the higher camps. Before this rule, tons of human waste accumulated on the mountain each season.
What It Costs
An Everest expedition is extraordinarily expensive. The Nepal government climbing permit alone costs $15,000 per person as of late 2025, up from $11,000 previously. On top of that, each team pays $3,500 for the permit application through a required local company, a $4,000 refundable trash deposit per climber, and $5,000 for a mandatory liaison officer. That’s over $24,000 in government fees before you’ve hired a single guide or bought a plane ticket.
Full-service guided expeditions, which include Sherpa support, supplemental oxygen, food, tents, and logistics, typically run between $30,000 and $100,000 or more depending on the operator. Budget operators on the lower end cut corners that can affect safety. Premium operators provide more oxygen bottles, better Sherpa-to-client ratios, and sometimes helicopter transfers to save time and energy on the lower portions of the route.
The Odds
A comprehensive study of 2,211 climbers during spring seasons from 1990 to 2005 found that the overall probability of reaching the summit was about 31%, with a 1.5% chance of dying on the mountain. That means roughly one in three climbers who attempted the summit actually stood on top, and about one in 67 died trying. Modern success rates have improved since that study period, largely because of better weather forecasting, improved supplemental oxygen systems, and more extensive fixed-rope infrastructure. Recent seasons have seen summit rates above 50% on good weather years, though the mountain still claims several lives nearly every season.
The causes of death are what you’d expect: falls, avalanches, altitude sickness, exhaustion, and exposure. Many fatalities happen on the descent, when climbers are depleted and less careful. The Khumbu Icefall, a shifting maze of massive ice blocks between base camp and Camp 1, remains one of the most dangerous sections despite being at a relatively low altitude. Climbers cross it on aluminum ladders lashed together over deep crevasses, often in the dark.
What Climbers Say About the Experience
Ask someone who has climbed Everest what it was like, and few talk about the summit first. They talk about the waiting. The weeks of doing nothing productive while your body slowly adjusts. The anxiety of watching weather forecasts for a summit window that may or may not arrive. The sound of avalanches rumbling in the distance. The strange camaraderie of living in close quarters with strangers who share the same obsessive goal.
Summit day itself is often described as anticlimactic in the moment. You’re too oxygen-deprived, cold, and exhausted to feel the elation you expected. That comes later, usually back at Camp 4 or base camp, when the reality of what you’ve done sinks in. Many climbers also describe a deep post-expedition emptiness, having spent months or years preparing for a goal that’s suddenly behind them.
The physical toll lingers. Weight loss of 10 to 20 pounds is common. Frostbitten fingers and toes are not unusual even on successful climbs. A persistent cough from the dry, cold air, sometimes called the “Khumbu cough,” can last weeks after returning home. And the mental images, the exposure, the moments of genuine fear on a ladder over a crevasse or in a bottleneck above 8,000 meters, stay with climbers for the rest of their lives.