Altitude sickness is the name given to a group of symptoms that can appear in people that climb to a high altitude. It’s also known as acute mountain sickness.
Altitude sickness can be experienced by anyone that chooses to ascend to high altitudes, and it happens due to a reduction in oxygen levels in the air.
Altitude sickness is completely preventable, and there are even treatments available to ease symptoms if they arise even after you’ve followed precautions, but the most important thing with altitude sickness is to rest for at least a full day before you continue your journey. Mild acute mountain sickness is treatable, and might not cut your adventure short – but if it isn’t treated in enough time, it can cause much more serious conditions, and require immediate descent and hospitalisation.
Dr. Diana Gall
Our Health Care Team
It's important not to ignore the signs of altitude sickness as it can become a medical emergency if you don't follow proper precautions. You should make sure you're prepared for the possibility of experiencing symptoms of altitude sickness as it can affect anyone, this means traveling with medicines to relieve the symptoms. Consider taking ibuprofen and paracetamol for headaches, anti-sickness tablets for nausea, and a drug to prevent and treat altitude sickness such as acetazolamide. It can take your body a few days to adjust to a change in altitude so take your journey slowly to let your body adjust and prevent serious altitude sickness.
Altitude sickness happens when you ascend to a level where the oxygen levels in the air begin to decrease. Whilst this sounds scary, there are various things that can be done to prevent acute mountain sickness – such as climbing mountains with an experienced guide, and making sure that you adhere to proper acclimatisation guidelines.
You’re more at risk of acute mountain sickness if you ascend to a high altitude too quickly, or without taking a break to get used to the height and oxygen levels.
Altitude sickness can quickly become an emergency, so it’s always important to know the early signs and symptoms so that you can act fast and avoid cutting your trip short.
Altitude sickness symptoms
Symptoms of altitude sickness usually start within a few hours to two days of reaching a high altitude, and the first signs you notice are likely to be a headache or nausea. The full list of symptoms for the mildest form of altitude sickness – AMS (acute mountain sickness) is as follows:
- Loss of appetite
- Shortness of breath
If you experience one or more of these symptoms during your ascent, the most important thing to do is to stop and rest – usually overnight. You should always alert a member of your group about your symptoms, even if you think it’s nothing to worry about. This means that you’ll be monitored for more serious symptoms. Acute mountain sickness doesn’t always mean that your journey will have to end early, but if it’s ignored and you push yourself too far with your symptoms, it can quickly become an emergency and turn into HACE or HAPE; both of which require immediate descent and hospitalisation.
HACE stands for high-altitude cerebral oedema, and is caused by swelling of the brain due to the decreased oxygen levels at high altitudes. Symptoms of HACE are slightly different to AMS, and in addition to nausea, vomiting, and headaches, can also include:
- Loss of coordination
If you have any of these symptoms at all, you MUST tell the leader of your group, as you’ll need to descent immediately, and likely take steroids and oxygen before you reach a hospital for assessment.
HAPE is another form of severe altitude sickness and stands for high-altitude pulmonary oedema. This happens when there is a build-up of fluid on the lungs. The symptoms of HAPE include:
- Blue-tinged skin
- Breathing difficulties
- Chest tightness
- Persistent cough
- Pink or white frothy sputum
Both HACE and HAPE can be life-threatening, but the best way to prevent it is to follow acclimatisation guidelines and to treat symptoms of acute mountain sickness as soon as you notice them.
Altitude sickness height
The good news for people that climb mountains in the UK is that you aren’t at risk of altitude sickness in this country, as our highest peak is only 1,345m and not high enough to induce acute mountain sickness.
Symptoms of altitude sickness generally begin at around 3,000m above sea-level, so if you’re going above this altitude abroad, you’ll need to make sure that you’re fully aware of acclimatisation guidelines.
Despite the fact that planes fly much higher than 3,000m, you won’t experience altitude sickness whilst flying, as cabins are pressurised to a level that we can deal with, and there’s plenty of oxygen for the journey. However, you should avoid flying directly to high altitudes, as the drop in pressure and oxygen levels will be sudden and you’ll be at a higher risk of HACE or HAPE.
Altitude sickness prevention
Luckily, altitude sickness can be prevented by following proper acclimatisation guidelines. It’s recommended that once you reach an altitude of 3,000m, you shouldn’t ascend more than 300-500m per day. It’s also recommended to take at least a 24-hour rest for every 600-900m climbed beyond 3,000m. This is to help your body to adjust to the new pressure and oxygen levels and to avoid becoming unwell.
Acclimatising properly can significantly reduce your risk of experiencing altitude sickness, but even if you follow recommended guidelines correctly, it’s still possible to feel unwell.
Altitude sickness medication
Whilst there isn’t a drug that’s specifically licenced to treat altitude sickness, acetazoleamide is commonly prescribed to combat symptoms of acute mountain sickness, and many mountain climbers are recommended it by their group leader. It isn’t always available through your own GP, but Doctor4U is pleased to offer it to those that are planning on travelling to high altitudes.
Acetazolamide is usually prescribed for glaucoma, and in some cases, epilepsy. However, it’s also been found to reduce many of the symptoms associated with altitude sickness, so is prescribed “off-label” for this purpose.
In addition to acetazolamide, you may also take painkillers such as paracetamol and ibuprofen for headaches relating to altitude sickness, and anti-nausea treatments for sickness. However, even if you feel better after treatment, you should still rest overnight to let your body get used to the new altitude, otherwise you risk becoming seriously ill.
Altitude sickness tablets
Altitude sickness tablets can be bought safely online from websites like Doctor4U. Acetazolamide is the most commonly used medication for altitude sickness, and our GMC-registered doctors can prescribe it to you after you’ve completed an online consultation form. If the doctor thinks the treatment is suitable for you, they’ll approve your order and generate a prescription which will be sent to our partner pharmacy electronically. This will then be shipped to your door.