How to avoid altitude sickness

Reducing your body's stress at high altitudes


At high altitudes, the air is thinner, which can cause altitude sickness as the body tries to adjust to decreased oxygen levels. Altitude sickness is also known as Acute Mountain Sickness (AMS). There are several methods to avoid and treat altitude sickness. Most of these methods involve reducing stress on the body as it adjusts to higher altitudes.


People can suffer from altitude sickness at different altitude levels. There are basic guidelines for acclimatisation to reduce the likelihood of suffering from altitude sickness. It is best to move to the area of higher altitude gradually. Avoid flying directly to high altitude locations (over 3000 meters), and progress upwards slowly. Guidelines recommend that you should take 2-3 days to adjust to high altitudes before ascending over 3000m. Avoid climbing 300-500m per day and take a rest day after every 600-900m you ascend or every 3-4 days. If you follow these guidelines and still experience altitude sickness, you should begin descending to a lower altitude.

Order effective treatment for altitude sickness

Product Img
Acetazolamide from £29.99
View all treatments

Stay Hydrated

At high altitudes, it can be hard to tell how much fluids you are losing through perspiration (sweating). Dehydration can mask other health problems as well. So it is important to stay hydrated. However, water can also dilute your sodium levels, so it is recommended to drink rehydration salts, to ensure that you maintain a healthy hydration balance.

Sleep at lower altitudes

If you're spending the day at high altitude, it is recommended that you descend to a slightly lower altitude to sleep. The lower oxygen levels at high altitude can reduce the quality of your sleep. Due to the low oxygen levels of oxygen, your body compensates by increasing your breathing rate, which leads to a higher oxygen and lower carbon dioxide level in the blood. The low carbon dioxide levels send signals to your brain to stop breathing, which results in sleep apnoea, where you stop breathing in your sleep for about 12 seconds before breathing again. 

Avoid alcohol, drugs and smoking

Smoking impairs lung function, which can reduce the amount of oxygen you take in at high altitude. Alcohol interferes with the absorption of oxygen by your blood, which may result in less oxygen reaching your brain. Alcohol may also increase your likelihood of dehydration. It is best to avoid taking drugs at high altitudes, as the effects can vary, but may interfere with your oxygen levels, hydration and overall health.

Eat Carbohydrates

Carbohydrates are a good source of energy. Unlike sugars, carbohydrates release their energy slowly, helping maintain stable energy levels throughout the day.

Use Acetazolamide (Diamox)

Acetazolamide is a form of medication used to prevent altitude sickness. For acetazolamide's prophylactic properties, it should be taken 1-2 days before ascending to high altitudes and continued as you climb higher. Acetazolamide should be used alongside the guidelines listed above to prevent altitude sickness.


How to identify altitude sickness:

Altitude sickness usually appears within 6-24 hours of reaching high altitudes (over 3000m). It can cause headache, nausea, vomiting, dizziness, tiredness, shortness of breath and loss of appetite, with the symptoms getting worse at night. If you experience any altitude sickness symptoms, you should let others know, as it could impair your judgement as the amount of oxygen reaching your brain is reduced. Never ignore altitude sickness, as it may progress to critical conditions such as brain/lung swelling caused by reduced oxygen levels.


What to do if you get altitude sickness?

If you start experiencing altitude sickness, stop ascending immediately and do not move to higher altitudes for another 1-2 days, until your symptoms have fully resolved. Ensure that you stay hydrated and consider taking rehydration salts to maintain your body's salt level. It is important to rest and avoid alcohol, caffeine and smoking. If you are suffering from headaches you can take some paracetamol or ibuprofen. If experiencing nausea, take some anti-sickness medication ( such as promethazine) to treat this. If you do not feel better within 24 hours, descend by at least 500m and wait 2-3 days for your symptoms to resolve before you start climbing again. 

View altitude sickness treatments



NHS > altitude sickness 

Livestrong > Drinking water at high altitude > Sleep at high altitude 

Gizmodo > do you really get drunker at high altitude ???????

Buy safe altitude sickness treatment from Dr Felix, your trusted online pharmacy


We’re a fully regulated UK pharmacy, with qualified
British doctors and happy customers.

Orders not approved will be fully refunded

Your trusted online doctor

Order now for delivery on Wednesday