Don’t let altitude sickness ruin the view. Get to know the symptoms, preventative measures & our top tips

So, you’ve planned a mighty hike, a trek up to the mountains or you’re jetting off to a place with high altitude – but have you thought about altitude sickness? 

Whether you’ve experienced it before or it’s completely foreign to you, learn everything you need to know so your next adventure is memorable for the right reasons. 

What is altitude sickness?

Altitude sickness, also referred to as acute mountain sickness (AMS), can occur when you ascend to high altitude, usually 2,500 metres above sea level, too quickly.

Your body can struggle to adapt to the lower levels of oxygen in the air, causing you to feel dizzy and experience difficulty breathing. If ignored, it can become a medical emergency. 

Who can get altitude sickness?

Believe it or not, age, gender or physical fitness have no connection to altitude sickness. In fact, it can affect anyone. 

Typically, mountain climbers and tourists travelling to cities that are 2,500 metres above sea level or higher, such as Bogotá in Colombia or La Paz in Bolivia, can experience altitude sickness.

• Did you know it's not possible to experience altitude sickness in the UK as Ben Nevis, the highest mountain, is only 1,345m?

Even if you have never experienced altitude sickness before, this doesn’t mean you won’t experience it on another occasion. So, it’s best to be prepared for the possibility of symptoms. It may be better to look at guided group tours before choosing your trip, as these often include a medical team or medical expertise.

How do you know if you’ve got altitude sickness?

The effects of altitude sickness can come on anywhere between six and 24 hours after ascending 2,500 metres or higher above sea level. 

Some of the most common symptoms you can experience are:

• Headache

• Feeling and being sick

• Dizziness

• Tiredness

• Shortness of breath

• Loss of appetite

It’s very important that you don’t ignore the symptoms of altitude sickness which can lead to serious health problems. If you have a severe headache or shortness of breath, you should descend immediately and seek medical help.

How to prevent altitude sickness 

If you’re planning on travelling 2,500 metres or more above sea level, there are a few preventative measures you can take so your trip can go ahead as planned.

• Avoid flying directly to a high altitude area, if possible

• Ascend slowly and take two to three days to get used to high altitude before going 2,500 metres above sea level 

• Have a rest day every 600 metres to 900 metres you go up (or rest every three to four days) 

• Drink plenty of fluids to stay hydrated 

• Have a rest day every three to four days

• Avoid climbing more than 300 metres to 500 metres per day

• Avoid smoking and alcohol

• Eat a light, high-calorie diet 

• Avoid strenuous exercise for the first 24 hours 

Top tips to alleviate symptoms 

1. Stop and rest where you are    

If you start feeling the effects of altitude sickness, stop where you are. 

2. Do not ascend for at least 24 to 48 hours

As frustrating as it might be, it’s important not to go any higher until you feel you have fully recovered. Staying at this altitude for at least a day will help your body to adjust to the higher altitude level.

3. Be prepared with pain relief medication 

If you are planning to climb up to a high altitude, be prepared with some ibuprofen or paracetamol, if these are suitable for you, and take these if you feel a headache come on. 

4. Take anti-sickness medicine

Before your trip, consider packing some anti-sickness medication in case you feel a wave of sickness come on during your ascent. Speak to a member of the pharmacy team or a pharmacist who will be able to advise what may be suitable for you. 

5. Make sure you're staying hydrated 

When the body is struggling to acclimatise to the change in oxygen levels, it’s imperative to drink enough water and stay well hydrated. This may help alleviate symptoms such as dizziness, too.

6. Do not smoke or drink alcohol

Having a healthy, balanced diet and lifestyle may benefit you for trips up to a higher altitude. If you’re experiencing symptoms of altitude sickness, it’s important not to smoke or drink alcohol.  

7. Avoid unnecessary exercise

Although exercise is part of a healthy lifestyle, in this instance it’s best avoided to prevent straining your body whilst you are experiencing symptoms of altitude sickness. It’s important to rest to allow your body to try and acclimatise. 

8. Plan routes for rapid descent

If you’re embarking on a hike to a high elevation, it’s a good idea to consider alternative routes in case anyone in your group becomes ill. Even a descent of 500 metres can be life-saving. So, if you don’t feel any better after resting for 24 hours, you should descend by at least 500 metres. You should not attempt to climb again until your symptoms have completely disappeared. 

If your symptoms do not improve or get worse, you should seek medical attention immediately. 

What happens if I ignore my symptoms?

If you experience moderate to severe symptoms but do not seek treatment, this can lead to life-threatening complications affecting the brain and/or lungs.

High altitude cerebral oedema (HACE)

Due to the lack of oxygen, your brain can begin to swell, known as high altitude cerebral oedema (HACE). This can develop in just a few hours and can be fatal if it’s not immediately treated. However, some people may not realise they are suffering from this, so it’s important to be aware of the symptoms.

Symptoms can include:

• Headache

• Weakness

• Feeling and being sick

• Loss of coordination

• Feeling confused

• Hallucinations (seeing and hearing things that aren’t there) 

If you’re travelling in a group, it’s important to look out for signs of HACE in others, as a person with HACE will often not realise that they are ill.

High altitude pulmonary oedema (HAPE)

High altitude pulmonary oedema (HAPE) is where fluid builds up in the lungs and symptoms can appear gradually, often a few days after reaching higher altitude. Again, if not treated immediately, the effects can be fatal. So, what symptoms should you look out for?

• Blue tinge to the skin or lips 

• Breathing difficulties, even when resting

• Tightness in the chest

• A persistent cough

• Bringing up pink or white frothy liquid 

• Tiredness and weakness

If you’re worried that you are experiencing the symptoms of either HACE or HAPE, move down to a lower altitude immediately, seek bottled oxygen if available, and get medical help – if you’re climbing there may be professional mountain climbers who have medical supplies with them. You should get to hospital as soon as possible. 

Altitude sickness prevention treatment 

For some, preventative medical treatment may be available if you’re planning to travel somewhere above an altitude of 3000 metres above sea level, if appropriate for you. Boots Online Doctor Altitude Sickness service* may be able to advise on what is best for you, following a consultation with a clinician.

To find out more about altitude sickness and preventative treatment, visit Boots Online Doctor or speak to your pharmacist or GP for further advice.

*Access to treatment is subject to a consultation with a clinician to assess suitability and eligibility. Charges apply.