Altitude Sickness is a condition that can affect any traveller or adventurer at high altitudes. It can not only make you feel ill and ruin your trip for a few days, it can also very easily become a medical emergency and become fatal. Here is everything you need to know about the prevention, symptoms and treatment of altitude sickness from a qualified medical professional.
I love the mountains. I am in awe of the sheer majesty of nature on display and love the thrill of the adventure it takes to drive, hike or climb them. Unfortunately on a recent trip through the Himalayan mountains I was unfortunately struck with AMS, or acute mountain sickness. We had ascended too high, too quickly above the 8000 feet minimum with not enough rest at specific altitude points, and I got hit hard and fast. To say that I felt like a tree being felled would not be all that much of a stretch.
My symptoms were heavy, especially the nausea and headaches. One of the benefits of being a qualified nurse means that I understand exactly what symptoms I could potentially get and that I knew what to watch out for too. I knew the best practice recommendations and knew that all I had to do was rest and acclimatize as well as a little symptom management, but despite knowing that it was still not the greatest experience.
This is why I want to pass on all of this essential information to everyone of you who may be thinking of heading up into higher altitudes on your round the world adventures so that you have everything you need to know to keep you safe and healthy.
So here are all the answers to your questions on Acute Mountain Sickness, the causes, symptoms, prevention and treatment from a professional qualified specialist nurse.
What is Altitude sickness?
Altitude sickness is a condition that can affect anyone at high altitudes above 2500 meters (8,200 feet). It occurs when the body has not had enough time to (or in some cases fails to) acclimatise to the fact it can not process as much oxygen at higher altitude. The higher you go without taking the time to acclimatise, the higher your chances of becoming affected.
Altitude sickness is not a singular disease with a specific set of absolute symptoms. It is a condition that ranges from a set of mild conditions that can be mildly unpleasant, to becoming increasingly worse and a condition that can deteriorate quickly and become fatal.
There are essentially three forms of altitude sickness.
- Acute Mountain Sickness (AMS)
- High Altitude Pulmonary Oedema (HAPE)
- High Altitude Cerebral Oedema (HACE)
What causes Altitude Sickness?
Altitude sickness is caused by ascending too high, too quickly. It is that simple. If your body has not had time to acclimatise through a slow ascent or has flown into altitude directly, then there is a chance you will experience symptoms of acute mountain sicknes.
Who can get Altitude Sickness.
Anyone can get Altitude Sickness, regardless of age, sex, health, physical fitness or any other factor. Experienced adventurers and climbers can get it just as easily as someone who has never climbed before.
Preventing Altitude Sickness.
There is no guaranteed way to prevent it completely but the best and only way to minimise your chances of getting altitude sickness is to ascend slowly and let your body acclimatise to the height you are at fully before going any higher.
Air pressure is much lower the further you get from sea level. This means that the amount of oxygen in the air is the same, but your body’s ability to absorb the amount of absolute oxygen in the lungs and blood is less and your SATS, or oxygen saturation (basically the amount of oxygen in your bloodstream) will be much lower.
Your body can adapt to these lower oxygen levels by creating more red blood cells to carry oxygen around in a process called acclimatisation. This means essentially ascending to high altitudes slowly with enough rest stops. It is important to note that even if you do this you may still develop symptoms of AMS and may still need to rest longer and slow your ascent. It can take anywhere from 2 to 3 days for your body to acclimatise but this does vary between individuals.
- Take at least 2 or 3 days of full rest at altitude before going above 2500 meters (8,200 feet).
- Climb no more than 300 to 500 metres a day if possible according to the Himalayan Rescue Society and Altitude.org.
- Have a full rest day every three days or sooner if you start developing symptoms.
- Stay well hydrated.
- Avoid alcohol.
Preventing Altitude Sickness when travelling with group tours.
Group tours have a higher risk factor of individuals developing symptoms of AMS than travelling with friends independently as they often have a set itinerary which may not suit every individual. If you choose a group tour you should ensure that:
- The trip is not rushed or too short for the heights that you want to reach.
- Avoids flying into areas of high altitude.
- Allows for acclimatisation days both before and during the trek.
- Has a gradual build up of any strenuous activity.
- Has knowledgeable, experienced staff and medical experts on hand in case of emergencies.
- Has plans and contingencies for descending if necessary.
- Has contingencies and facilities available for medievacs if necessary.
Symptoms of Acute Mountain Sickness.
Acute mountain sickness is the mildest form of altitude sickness and the two terms are often used interchangeably. Symptoms can affect different people very differently and vary greatly in their extremity, height at which they occur and speed of onset.
- Loss of appetite
- Nausea or vomiting
- Fatigue, flu like symptoms
- Mild insomnia.
How to diagnose Acute Mountain Sickness.
AMS can be diagnosed in adults using the a self assessment tool known as the Lake Louise Symptom Score.
If you are climbing or ascending above 2500 meters (8,200 feet) and have a score of 3 or more, then you should be diagnosed with AMS and take steps to prevent further deterioration and improve your condition.
Treating altitude sickness or acute mountain sickness.
Treating acute mountain sickness is relatively simple and mostly involves rest and the treatment of any symptoms that may occur.
It is really important you let any travel companions or hostel/guesthouse staff know about any symptoms so they can keep an eye on you, as symptoms can present very quickly and your judgement may become clouded.
If symptoms are mild and are being managed well then rest then staying at the elevation you are, not going any higher, resting and staying hydrated are the best things you can do. Despite common misconceptions it is not always necessary to go down to a lower elevation straight away.
If you develop any of the symptoms of AMS:
- Stop and rest.
- Do not go any higher for at least 24 to 48 hours.
- Don’t do any strenuous exercise.
- Stay well hydrated.
- Treat any symptoms you may have with Ibuprofen for any headaches and an antiemetic (anti sickness) such as Promethazine.
If symptoms persist for more than 48 hours with no sign of getting better:
- Go down at least 500 metres (1640 feet) in elevation.
- Continue with the above advice for at least another 24 – 48 hours.
Your body should acclimatise in 2 to 3 days but this changes depending on the individual and could take a little longer. If after 2 or 3 days of coming down you are still experiencing symptoms with no sign of improvement at all then seek medical advice. Don’t attempt to climb again until your symptoms have improved.
Should I travel with medication for altitude sickness?
Some general and basic medication is always a good idea in a good emergency first aid kit, but there is no need to go overboard. All you need are:
- Analgesics such as Ibuprofen or at least Paracetamol for headaches.
- Antiemetics (anti sickness medication) such as Promethazine for nausea.
- Acetazolamide (Diamox) for reducing the symptoms of altitude sickness, but this is not a foolproof medication, may need a trial at sea level to discount any side effects before ascending, should never be used as a replacement for ascending slowly and is not prescribed in every situation. Please consult a medical professional at your GP surgery or Travel Clinic for specific one to one advice.
Whatever medication you do bring, it is still advised to follow all preventative measures and not ascend too quickly.
It is also extremely important to remember that there are a wide range of alternative medications, foods and products (such as chocolate or coca tea) that are sometimes recommended to reduce AMS symptoms, but there is not enough clinical evidence to actually support the advisement of any of these products.
Any recommendation to use any of these alternatives in this way should be heavily discouraged as they do not work and can lead to a dangerous false sense of security.
HAPE and HACE. Medical emergencies.
If AMS is ignored and you continue to ascend and go to higher altitudes then you may develop complications of AMS and there is a real risk of developing HAPE and HACE.
High Altitude Cerebral Oedema (HACE) and High Altitude Pulmonary Oedema (HAPE) are the two serious forms of altitude sickness complications, are potentially fatal and are considered medical emergencies.
High Altitude Cerebral Oedema (HACE).
HACE is caused by a cerebral oedema, a swelling of the brain. It is a relatively rare but very serious complication of ignored AMS.
Symptoms can include:
- Severe headache.
- Unsteadiness and drowsiness (may present as looking ‘drunk’).
High Altitude Pulmonary Oedema (HAPE)
HAPE is caused by fluid gathering in the lungs, possibly caused by fluid leaking from blood vessels due to increased pressure into the lungs and air sacs, causing a pulmonary oedema. This can be fatal.
Symptoms may include:
- Possible audible sounds when breathing such as rales or crackles.
- Tachycardia and increased pulse rate.
- Cyanosis (a bluish discolouration of the skin), especially at the extremities such as fingers.
Treatment of HACE and HAPE.
Both conditions are medical emergencies and can be rapidly fatal; descent must be carried out immediately.
Anyone showing signs of HACE or HAPE should be medically evacuated as soon as possible, by air evacuation or by carrying them down if necessary as further exertion may make their condition worse.
In medical evacuations a portable hyperbaric chamber known as a Gamow bag may be used. This is essentially a large portable chamber that simulates a lower altitude environment by up to 7000 feet whilst descent is taking place.
When access to a medic or medical facility is available, those showing symptoms of HACE will be given oxygen therapy and Dexamethosone, which is a corticosteroid medication used in this instance to reduce swelling on the brain. A period in hospital is inevitable for observations and follow up treatment.
Those patients showing signs of HAPE will after being evacuated to a medical facility at a lower elevation be given oxygen therapy and Nifedipine to reduce pulmonary arterial pressure and ease breathing.
Finally the best piece of advice is to make sure you are fully covered by an extensive medical insurance policy. Remember that anyone can get altitude sickness at any time at elevation, and if you are planning on doing some climbing or hiking above 2500 meters (8,200 feet) then you really should make sure your insurance policy covers you, and that means not just for the illness and treatment itself, but for the medical evacuation costs, the helicopter, the specialist equipment and even if necessary repatriation. Costs can be in the tens of thousands at bare minimum, and you really don’t want that bill at the end of it just to save yourself a hundred pounds or so.
Did you enjoy this article? I would love to hear your thoughts in the comments section below or on my Facebook or Twitter pages and please feel free to share it with any or all of the social media buttons. If you want to get more great backpacking tips, advice and inspiration, please subscribe to updates via email in the box to your right.