Altitude sickness (also known as acute mountain sickness) is a problem which is common in climbers who reach a high altitude too quickly, without giving their body time to adjust to the changes. Common symptoms include headache, dizziness, nausea and shortness of breath. It is particularly common in climbers and skiers when they are 2,500m (8,000 feet) above sea level. People of any age can be affected by this problem. You can buy altitude sickness tablets from Medicine Direct. Browse our range of products for this condition below.

Altitude Sickness

We can't find products matching the selection.

What is Altitude Sickness?

Altitude sickness is when you are unable to breathe properly at high altitudes due to not being able to take in enough oxygen. Altitude sickness is also referred to as acute mountain sickness. If it is ignored, it can become a serious medical emergency.

Typically, altitude sickness only occurs in high altitude conditions above 2,500 metres (8,000 feet), although some people can also experience symptoms at lower altitudes.

This problem is most common among climbers who reach a high altitude too quickly, but it is not uncommon for skiers to suffer from altitude sickness either.

Around 20% of people who climb above 2,500m are affected by altitude sickness. While some people are more susceptible than others, your age, sex and level of physical fitness have no impact on your risk of developing altitude sickness; it can occur in anyone. Furthermore, you are no less likely to experience symptoms of altitude sickness just because you have never suffered from the problem on a previous trip. Symptoms usually become severe when people go any higher than 3,600m (12,000 feet).

Various techniques can be applied to aid acclimatisation to high altitudes, and there are also altitude sickness tablets like Diamox available to ease the symptoms.

Altitude Sickness Symptoms

If you have ascended a high altitude too quickly, the symptoms of altitude sickness can appear anywhere between 6 and 24 hours later. Altitudes of 2,500m or higher can induce these symptoms. Symptoms are usually worst at night.

Normally, you will feel generally unwell, similar to having a hangover.

Mild symptoms of altitude sickness may include:

  • Difficulty sleeping
  • Increased heartrate
  • Loss of appetite
  • Feeling tired
  • Upset stomach
  • Feeling sick or being sick
  • Feeling dizzy or unsteady on your feet
  • Shortness of breath

Some people may suffer from more severe symptoms of altitude sickness, which may include:

  • Feeling drowsy
  • Feeling confused
  • Feeling breathless
  • Lack of co-ordination and/or difficulty walking
  • Convulsions (fits)
  • A persistent cough
  • Coughing up frothy liquid which is pink/white
  • Bubbling sounds in the chest
  • Double vision
  • Behaving irrationally

These symptoms can affect mountain climbers and tourists who visit destinations that are at least 2,500m above sea level.

High altitude cerebral oedema (HACE)

You must never ignore the symptoms of altitude sickness. If you suffer from any of the symptoms listed above and they are ignored, it can lead to life-threatening conditions that affect the lungs or the brain.

Aside from altitude sickness, you may also develop high altitude cerebral oedema (HACE), which is swelling of the brain as a result of a lack of oxygen.

You may be suffering from HACE if you have any of the following symptoms:

  • Feeling weak
  • Headache
  • Hallucinations
  • Feeling confused
  • Loss of coordination
  • Feeling sick or being sick

High altitude pulmonary oedema (HAPE)

High altitude pulmonary oedema (HAPE) is when fluid builds up in your lungs.

You may be suffering from HAPE if you have any of the following symptoms:

  • Tightness in your chest
  • A persistent cough
  • Coughing up white/pink frothy liquid
  • Feeling tired or weak
  • A blue tinge to the skin on your lips

These symptoms may start to appear after a few days of being in a high altitude. If not treated immediately, this condition can also be life-threatening.

Causes of Altitude Sickness

Altitude sickness (acute mountain sickness) commonly affects climbers when they reach a high altitude too quickly. It is caused by the reduced air pressure and lower levels of oxygen at high altitudes. The faster a person climbs to a high altitude, the more likely they are to suffer from altitude sickness symptoms.

The most effective way to prevent altitude sickness is to ascend to the high altitude gradually, over the course of a few days. This will allow your body to acclimatise to the new environment.

You are at a greater risk of suffering from altitude sickness if:

  • You make a rapid ascent
  • You have not acclimatized to the high altitude
  • You have any medical conditions which affect either your heart, nervous system, or lungs
  • You live at or near sea level and travel to a high altitude
  • Alcohol or any other substances have interfered with the acclimatisation
  • You have suffered with this problem before

Diagnosing Altitude Sickness

If you start to get symptoms of altitude sickness, you should stop and rest where you are. Even if you are only experiencing mild symptoms of the condition, make sure that you tell your travel companions. Altitude sickness can impair your ability to think clearly, so there is a chance that your judgement may not be completely clear.

You can continue on your journey once your symptoms have gone away and you feel better again.

If it has been 24 hours since you started to feel unwell, and your symptoms have not improved, you should go down by at least 500m (approximately 1,600 feet). You should rest until your symptoms have gone away. Do not climb again until your symptoms have completely disappeared.

After around two days, your body should have acclimatised to the high altitude and your symptoms should have gone away. If they have not gone away or get worse, you should seek medical attention as soon as possible.

Altitude Sickness Treatment

Preventing altitude sickness

There are various things you can do to ease the effects of mild altitude sickness and to aid acclimatisation. To lower the risk of suffering from altitude sickness, you should take the following precautions:

  • Stay hydrated but avoid alcohol
  • Do not smoke
  • Rest as much as you can
  • Do not take any sleeping pills
  • Take at least two days to used to high altitudes before ascending higher than 2,500m
  • Eat a light but high-calorie diet
  • If possible, avoid flying directly to high altitude areas
  • Have a rest day every 600m to 900m you ascend, or rest every 3 to 4 days
  • Avoid climbing more than between 300m and 500m a day
  • Do not exercise strenuously for the first day

You should agree with your travel group that you will keep each other updated on how you are all feeling. This will help everyone to remain alert in spotting symptoms of altitude sickness in themselves and those in their travel party.

Can you buy altitude sickness tablets over the counter?

Various tablets for altitude sickness are available to buy, both over the counter and on prescription, either to ease your symptoms or prevent you from experiencing this condition.

The likes of ibuprofen and and paracetamol can be taken to ease the pain from headaches, if you suffer from them during your trip.

If you start to feel sick, you can take an anti-sickness medicine such as promethazine. This medicine can also work to prevent vomiting, which is one of the symptoms of altitude sickness.

How does Diamox work for altitude sickness?

Acetazolamide (generic Diamox) tablets are an effective medication for both easing and preventing milder cases of altitude sickness. Acetazolamide (Diamox) works to correct the chemical imbalance that goes on in your brain when you are at a high altitude.

Taking Acetazolamide (Diamox) can also reduce the recovery time of mild altitude sickness from between 24 and 48 hours to between just 12 and 24 hours. This is dependent on you not ascending any higher during this time, allowing for acclimatisation.

If you are ascending quickly and not leaving time for acclimatisation, taking Acetazolamide (Diamox) can also help to prevent altitude sickness. It is never advised that you ascend to high altitudes too rapidly. If you climb to a high altitude too quickly, without getting used to the new altitude conditions, you are still at risk of suffering from severe altitude sickness. This can result in a medical emergency which may require immediate descent for medical treatment.

It is important to remember that, even when taking Acetazolamide (Diamox), you still need allow time for acclimatisation before you start ascending again. Never ascend any higher until your symptoms have completely gone. Never use Acetazolamide (Diamox) tablets as a medication to endure the symptoms of altitude sickness so you can continue to climb.

You may experience mild side effects when you take Acetazolamide (Diamox), but these side effects will not occur in everyone. You may have:

  • Fatigue
  • Irritability
  • Slight numbness or tingling in the face, fingers or toes
  • Dizziness
  • Loss of appetite
  • Changes in taste
  • Thirst
  • Headache
  • Flushing

Most doctors will recommend taking a trial dose of Acetazolamide (Diamox) a few days before you start travelling. This will see if you do suffer any side effects of this medication.

We recommend visiting the NHS Fit For Travel website to explore more on the topic of altitude sickness. 

Is Diamox over the counter?

Acetazolamide (generic Diamox) is a prescription-only medicine. You can buy Acetazolamide tablets following a simple and confidential online consultation with a registered doctor at Medicine Direct. The doctor will review your answers and issue you with a prescription for Acetazolamide if they believe that it is a safe medication for you to take to prevent altitude sickness.

You can then use this prescription to buy your medication from our registered online pharmacy. Never order medicine online unless it is from a UK registered pharmacy that is regulated by the General Pharmaceutical Council (GPhC), like Medicine Direct.

If you place your order with us by 2pm, we can also offer you next day delivery.

Can you buy altitude sickness tablets over the counter?

No, this medicine requires a prescription. However it can be purchased online from a number of pharmacies.

A medicine like Acetazolamide (Diamox) requires a prescription from a doctor for you to be able to buy it.

However, you can purchase medicines like ibuprofen and paracetamol over the counter. These medicines can help with some of the symptoms of altitude sickness, such as nausea.

What is altitude sickness?

Altitude sickness is when your body cannot take in enough oxygen to function properly at high altitudes. It is separated into two conditions: mild and severe altitude sickness.

What causes altitude sickness?

Altitude sickness is caused by climbing to levels higher than 2,500m (8,000ft) above sea level.

The higher you climb, the lower the atmospheric pressure gets, making it harder for you to get the oxygen that your body requires to function properly.

The milder symptoms of altitude sickness include:

  • Difficulty sleeping
  • Increased heartrate
  • Loss of appetite
  • Feeling tired
  • Upset stomach
  • Feeling sick or being sick
  • Feeling dizzy or unsteady on your feet
  • Shortness of breath

Severe cases of altitude sickness may induce the following symptoms:

  • Feeling drowsy
  • Feeling confused
  • Feeling breathless
  • Lack of co-ordination and/or difficulty walking
  • Convulsions (fits)
  • A persistent cough
  • Coughing up frothy liquid which is pink/white
  • Bubbling sounds in the chest
  • Double vision
  • Behaving irrationally

What can make altitude sickness worse?

This condition can be exacerbated by alcohol and cigarettes.

You should not ignore signs of altitude sickness if you have any of them; do not try to push through them and continue ascending to higher levels. Mild cases of this condition can be mad more serious if you ignore the signs, which can be very dangerous.

How do I prevent altitude sickness?

There are certain precautions you can take to lessen the risk that you will suffer from this problem.

Below is a list of precautions you should take to lessen the risk that you will suffer altitude sickness:

  • Stay hydrated but avoid alcohol
  • Do not smoke
  • Rest as much as you can
  • Do not take any sleeping pills
  • Leave at least two days to used to high altitudes before ascending higher than 2,500m
  • Eat a light but high-calorie diet
  • If possible, avoid flying directly to high altitude areas
  • Have a rest day every 600m to 900m you ascend, or rest every 3 to 4 days
  • Avoid climbing more than between 300m and 500m a day
  • Do not exercise strenuously for the first day

What medication can I use to prevent/treat altitude sickness?

One of the most effective medicines you can use for altitude sickness is Acetazolamide (Diamox). This treatment can work to ease and prevent altitude sickness. It can reduce the symptoms associated with rapid ascents, such as dizziness, nausea, headaches and shortness of breath.

Acetazolamide works to correct the chemical imbalance that goes on in your brain when you are at a high altitude.

Acetazolamide tablets can cut your recovery time in half, although you should not climb to a higher altitude until all of your symptoms have disappeared completely. You must still allow time for acclimatisation, to help your body adjust to the new altitude.

Normally, you will be instructed to start taking Acetazolamide one or two days before you start ascending to higher altitude conditions. You will then keep taking it every day, completing your course of treatment 48 hours after you have reached the highest altitude.

Do I need to see a doctor for altitude sickness?

Mild cases of altitude symptoms can normally be treated by resting, taking medication and allowing your body to acclimatise to the new altitude.

Severe altitude sickness will require medical treatment from a doctor; you will need to descend to a lower level as soon as you can.

What complications can altitude sickness cause?

Altitude sickness can cause complications if the signs of it are ignored

Ignoring the signs of altitude sickness can result in high altitude cerebral oedema (HACE), which is swelling of the brain due to a lack of oxygen. If you have any of these signs, you may be suffering from HACE:

  • Feeling weak
  • Headache
  • Hallucinations
  • Feeling confused
  • Loss of coordination
  • Feeling sick or being sick

Another problem you may suffer from is high altitude pulmonary oedema (HAPE), which is when fluid builds up in your lungs.

You may be suffering from HAPE if you have any of the following:

  • Tightness in your chest
  • A persistent cough
  • Coughing up white/pink frothy liquid
  • Feeling tired or weak
  • A blue tinge to the skin on your lips

Make sure you seek treatment as soon as possible if you notice any of the above. Without medical attention, this could be life-threatening.

Is it safe to buy altitude sickness treatment online?

Ordering medicine online from Medicine Direct is completely safe. We are a fully-registered UK pharmacy, regulated by the General Pharmaceutical Council (GPhC), which means that all of the medical products we sell are safe and approved by the Medicines and Healthcare products Regulatory Agency (MHRA).

All of our doctors and pharmacists are registered with the General Pharmaceutical Council (GPhC), the General Medical Council (GMC) and the MHRA, meaning that they are legally qualified to prescribe medication just like your local GP.

We offer a fast delivery service, despatching your medication in discreet packaging, and if you order by 2pm we can have your medicine with you the very next day.

Doctor Notes

Medicine Direct have an experienced clinical team of doctors, pharmacists and dispensers, all of whom are based in the UK. All are fully trained and qualified to provide appropriate and considered care across all areas of treatment we have available at our online pharmacy.

This means that no matter which member of our team is assigned to your case, you can rest assured that you are in the hands of a highly skilled medical professional, who possesses the compassion and clinical expertise to properly advise you on the best course of treatment.

We are fully regulated

All of our doctors and pharmacists are fully registered with both the General Medical Council (GMC), MHRA and the General Pharmaceutical Council (GPhC). Each member of our team has also worked in various clinic settings in the past, such as community pharmacies and NHS hospitals.

Sonia Khan Medicine Direct Pharmacist

Sonia Khan
MPharm: 2076091


Pharmacist

This content has been written by our Pharmacist Sonia Khan and has been medically reviewed by our Superintendent Pharmacist Hussain Abdeh

View Profile
We’re here to help

If you need any help, don't hesitate to get in touch, we would love to hear from you!

Copyright © 2021 Pharmacorp LTD. All rights reserved.