What are the symptoms? How can I prevent high altitude sickness? What to do when symptoms occur? Is there any medical treatment?
Before we went to Morocco to climb Toubkal (4167m), I did some research on altitude sickness to get prepared for the worst case. Altitude sickness occurs when you climb too high too quickly. And anyone can get it; irrespectively of age, gender or physical condition. Mild forms of altitude sickness occur in 2,500m (8,000 feet) above sea level. The reason is that the air gets thinner and contains less oxygen. In 3000m the athmosphere’s oxygen is half of that on sea level. In 5000m it’s about a third. That means with every breath you take you breathe in less oxygen than your body actually needs. Your body couldn’t adapt to the new conditions quickly enough. More severe symptoms of altitude sickness usually occur at high altitudes above 3600m (12000 feet).
Types and symptoms of altitude sickness
There a 3 different forms:
1) Mild altitude sickness or acute mountain sickness (AMS): It can occur in high altitudes above 2500m (8000 feet). Common symptoms are similar to a hangover: headache, nausea including vomiting, exhaustion and dizziness. About 50% of people who live in lower altitude and ascend above 3000m suffer from acute mountain sickness.
2) High altitude pulmonary edema (HAPE): High altitude pulmonary edema is a more severe type of altitude sickness. Pink, frothy fluids build up in the lungs and cause a bubbling sound in the chest, coughing up liquids and breathlessness. Additionally, heart rate and body temperature can raise and lips turn blue. The person suffering from HAPE has to descend immediately.
3) High altitude cerebral edema (HACE): High altitude cerebral edema is a build-up of fluid in the swelling brain and causes difficulties to walk in a straight line, blindness, confusion, drowsiness leading up to loss of consciousness. HACE is life-threatening and requires immediate action as well as medical attention. It’s an extremely rare condition; about 1% of people ascending to 4000m get HACE and occurs mostly when symptoms of HAPE have been ignored.
Prevention and altitude sickness treatment
The golden rule to prevent high altitude sickness: get used to the high altitude above 2600m which usually takes a few days. Example: the body needs about 7 days to acclimatise to an altitude of 5000m (16400 feet). Give your body time to adapt and don’t ascend higher than 1000m a day, but more important: don’t sleep higher than 500m (1600 feet) than the night before. Stay hydrated. Drink lots of water; no alcohol!
If you do get symptoms of mild altitude sickness, don’t go higher in the next 24-48 hours. Wait until your symptoms improve and then you can continue climbing. If they don’t improve descend by at least 500m (1600 feet).
In case of high altitude pulmonary edema and high altitude cerebral edema you need to descend immediately to a significantly lower altitude (at least 1000m) and seek medical help. Again: HAPE and HACE are life-threatening conditions and need to be taken cared of instantly. Giving additional oxygen or drugs like Nifedipine or dexamethasone may help temporarily but are no substitute for getting off the mountain.
Altitude sickness medication
1) Pain killers: A common medication among climbers and trekkers to treat symptoms of mild altitude sickness or acute mountain sickness are pain killers such as paracetamol and ibuprofen.
2) Diamox: Acetazolamide (Diamox) can reduce severe symptoms like nausea or even prevent symptoms. However, opinions about it are divided. Research has shown that it can be effective but some climbers didn’t feel a difference after taking it. Side effects of Diamox can be tingling feet and fingertips and fizzy drinks can taste funny.
3) Nifedipine: Nifedipine can be used to treat high altitude pulmonary edema: It lowers the pressure on arteries in the lungs and improves chest tightness and helps to breathe more easily. It is usually prescribed to lower high blood pressure. So be careful when standing up.
4) Oxygen: In case of HAPE and HACE, the person should be given oxygen in order to balance out the lack of oxygen. But also people with mild symptoms will feel relief.
5) Portable hyperbaric chamber: The portable hyperbaric chamber is a tent that can provides an airtight seal. It is inflated to a significant pressure above ambient atmospheric and simulates a descent of 2000m. The hyperbaric chamber has shown effective for the treatment of HACE.
I suffered from mild altitude sickness when we climbed Toubkal, North Africa’s highest mountain. We took the car to Imlil (1740m) and starting trekking from there. Our first stop was Les Mouflons (3207 meters), Toubkals refuge, where we stayed over night. Until then I was fine. Next day we were supposed to summit, climbing another 960m. By then I had a slight headache, but I felt generally okay. Close to the summit, only 100 meter away in height, we had a snack to wait for the rest of our group members. I was eating chocolate, nuts and raisins. I thought it was a good idea to gain some energy, but it really wasn’t! 10 minutes later nausea kicked in. Oh man! My memories of that are still very vivid. I didn’t throw up, but I significantly slowed down on the way to the summit in order not to do exactly that. I felt better when we descended down to the refuge again, but still felt a little nauseous and had a bit of a headache that night. We went for another climb the next day and I was completely exhausted. But I don’t really know if that was due to the altitude sickness or the tough climb from the day before. I must say, I didn’t really enjoy suffering from altitude sickness *surprise*. It gave the whole climbing experience a bit of a bitter taste. It took me a while to forget about it and concentrate on the key moments, standing on top of the summit, looking over the entire Atlas mountains in a 360° circle, the quietness up there. I played with the idea of doing Kilimanjaro (Africa’s highest mountain), but I dropped that idea after climbing Toubkal. I read so many blog articles of people climbing Kili and literally puking their guts out on the way up. No thank you. I don’t have any ambitions to climb in high altitude unless I have enough time to adjust to the conditions.
READING TIP: If you want to read more about a real situation of high altitude sickness, read the bestseller ‘Into Thin Air: A Personal Account of the Mt. Everest Disaster.’ Here, Jon Krakauer describes the effects of HACE upon one of his fellow climbers, Dale Kruse.