Adventures — 20 June 2021 at 6:06 pm

At the Height of Expedition Medicine; The Mount Everest Marathon

Dr Nishma Shah / GP Partner / London

With a starting altitude of over five thousand metres, Bufo Ventures’ Mount Everest Marathon is recognised by the Guinness Book of World Records as the world’s highest marathon. Dr Nishma Shah shares her experiences of working within the team of doctors covering this unique event.

Spectacular lake views

The Everest Marathon

The Everest Marathon was first organised in conjunction with Bufo Ventures, a company set up by Diana Sherpani in 1987, and has continued to run in the autumn since this time. With a starting altitude of above 5164m, it is recognised in the Guinness Book of World Records as the world’s highest marathon. I was fortunate to work as one of six medics covering two consecutive events in 2015 and 2017.

The Route

This unique race navigates the high Sherpa trails of the Khumbu valley, descending in altitude by over 1500m throughout its 26.2 mile course. The race start line is located at Gorak Shep, a frozen, sand-covered lake bed located at 5164m. This was the previous home of Mount Everest’s base camp. The surrounding mountains provide sublime views and magical light, undisturbed except for a few visible tea houses. The race route descends along the scenic trekking path, finishing at an altitude of 3440m in the Sherpa “capital” of Namche Bazaar. Despite its net descent in altitude there are undulations throughout, with river crossings, high altitude passes, and notable climbs to tackle en route.

As the “sweep doctor” in 2017, I completed the full marathon behind the last of the runners to ensure that everyone returned safely to Namche, with a total time of 11 hours on foot.


As with most expeditions, preparation for this race started long before setting off to Nepal. Our chief medical officer carefully reviewed runners’ applications to ensure there were no medical conditions that could affect their ability to complete the race. Previous running experience along with time at altitude were also taken into account given the nature of this race.

As doctors it was essential for us to be well prepared and able to practice comfortably in this environment, with overnight temperatures dropping to -20 degrees Celsius at altitudes of greater than 4000m. Ensuring that our team were physically fit, with no history of altitude illness requiring treatment or evacuation, as well as being able to survive and thrive in a low-resource setting with basic facilities was crucial.

In the run-up to the race, much effort was put into ensuring that our medical kit was well stocked, relevant, and up to date. Specific medical kit considerations for this race included splints, a Gamow bag for altitude sickness, and oxygen cylinders, all of which were sourced from Kathmandu on arrival. We also identified the limited number of rescue posts on the trek and the facilities available at each, in the event that we may need to evacuate a participant. The nearest rescue posts are located at Machermo and Gokyo and the closest hospital facilities and clinics are near Namche and Phakding. Given the relatively basic facilities at the local hospitals, patients requiring evacuation for moderate to severe altitude sickness are generally evacuated to larger hospitals in Kathmandu.

On arrival in Kathmandu, we spent 2 days finalising our preparations, including sourcing the remaining medical equipment, as well as performing basic medical assessments on all participants to record their baseline vital observations. This gave us the opportunity to meet the race participants and discuss the race ahead.

Nepal mountain landscape

Journey to the Start Line

The full journey spanned three to four weeks from start to finish which included a two-week period of acclimatisation for the runners and team members to adapt to high altitude prior to the marathon.

The two-week trek is designed for acclimatisation before race day and includes an enforced rest day for every 1000m gained in altitude. On arrival to Namche the participants are given the opportunity to take part in a six-mile fun run, which makes up the final loop of the marathon. Participants also have the opportunity to walk up to Gokyo Ri and Kala Patthar peak which are both above 5000m. The views from these peaks are simply breathtaking and provide a great opportunity to further acclimatise and prepare for marathon day.

Throughout the expedition and acclimatisation period, we recorded daily peripheral blood oxygen saturations as well as heart rates for each participant. There was a doctor on call 24 hours per day, with an additional doctor tasked to walk at the back of the group. Their role was to monitor those who may be struggling with the altitude, and assess and manage participants if medical issues arose. It is necessary that supervising doctors remain vigilant, as the initial symptoms of altitude sickness can be extremely subtle and varied, with rapid progression.

Memorable Cases on the Mountain

Case 1 – High Altitude Pulmonary Oedema (HAPE)

The most acutely unwell patient we looked after was a 48-year old male who started to experience difficulties trekking between 3500-4000m.  He was identified as looking slightly grey throughout the day, and on arrival at camp that evening his peripheral oxygen saturations were below 60% in air. After checking the probe multiple times and ensuring that his peripheries were warm and well perfused the saturations remained consistently below 60%. Clinically he was sitting up and talking in full sentences with no evidence of respiratory distress or cyanosis, which did not seem to be in concordance with his numerical medical observations.

Whilst in bed that evening he developed a cough and had some difficulty sleeping which was not raised with the medical staff overnight. The following morning it became clear that he was having difficulty getting up, was unable to lie flat due to breathlessness, and that his cough had progressed to being productive of frothy sputum.

We initiated symptom management for HAPE with oxygen and nifedipine on the mountain, whilst arranging emergency helicopter evacuation to hospital in Kathmandu, where he received supplementary oxygen and antibiotics for pneumonia.

Whilst this was a difficult decision to make, as a team we had identified that he needed to descend urgently and access treatment in a local medical centre, and we were able to arrange this whilst keeping the rest of the team and participants safe. We later found that this participant had experienced altitude illness on previous trips which had not been disclosed to the medical team. A consideration for this participant would have been prophylactic acetazolamide and very careful monitoring throughout the event if we had been aware of this.

The definitive treatment for HAPE is descent. HAPE can vary in degree from mild to potentially fatal, and a timely descent is essential in moderate to severe cases. A Gamow bag can be used as a temporary measure to simulate a descent until more definitive means to descend can be arranged. Mild presentations may respond to additional rest days, increasing fluid intake and reducing the speed of ascent, however careful monitoring is essential.

Planning for casualties

Case 2 – Acute Mountain Sickness (AMS)

The second case was mild altitude sickness in a young and very fit runner who ascended quickly from 2600m to 3444m on day two of the trek. This caused the candidate to experience severe headaches and nightmares, with difficulty sleeping. We managed the case conservatively and advised the participant to take time ascending slowly and steadily. It can be very tempting to walk quickly and arrive first at the destination, but the only prize in this case was a headache and mild case of AMS.

Gastroenteritis in Camp

An outbreak of gastroenteritis can prove difficult to manage in this remote setting, and puts participants at risk of dehydration and altitude sickness. Despite advice surrounding eating out and ensuring preventative measures such as optimal personal hygiene and sanitation, there was an outbreak early on in the 2017 event. The importance of handwashing is drummed into everyone throughout the expedition; with hot water and soap provided at the entrance of all tea houses and prior to meals.  Sharing food is discouraged and the use of serving spoons and individual plates for snacks is strongly encouraged. Campylobacter is a very common cause of gastroenteritis in Nepal, with multiple cases of resistance found in recent studies. With good sensitivity to the antibiotic azithromycin, we made sure to carry ample supplies in our medical kits. During the 2017 race we had an outbreak of at least ten participants suffering from diarrhoea and vomiting. As a result, I spent many evenings attending to patients with loperamide, azithromycin, and oral rehydration, as well as arranging for repatriation of some to Namche Bazaar.


Working on the Everest marathon was an amazing and enriching experience; highlighted by spectacular scenery, the personal and professional challenges of working in a low resource setting, and making great friends along the way. The journey tests you both physically and mentally, and you learn a great deal about yourself.

Take-home Messages

  1. Actively monitor participants for subtle signs of altitude illness and initiate early management.
  2. Encourage open and honest conversations regarding previous illness at altitude.
  3. Have clear isolation protocols in place to prevent the spread of diarrhoea and vomiting throughout a camp.
  4. Reflect on the expedition, keep clear records and ensure that a debrief takes place to discuss medical cases and changes required for future trips.