With increasing numbers of people travelling to more remote and exotic locations, journeying to high altitudes has becoming more popular than ever. High altitude is generally defined as any height between 1,500 and 3,500m, with 3,500 - 5,500m being classed as very high altitude and anything over 5,500m classed as extreme altitude.
Altitude sickness can occur when you move between altitudes occurs too quickly for acclimatisation to take place effectively. Mild forms of altitude sickness are known as acute mountain sickness (AMS), while more severe forms can develop into high altitude cerebral oedema (HACO) or high-altitude pulmonary oedema (HAPO).
Symptoms of mountain sickness can change depending on what form of illness you have developed, and how severe it is. The most common symptoms of altitude sickness include dizziness, fatigue, shortness of breath, loss of appetite, lethargy and sleep problems. In more severe cases, these symptoms become worse and are accompanied by headaches, nausea and vomiting, as well as a tightness in the chest. In the most serious cases, the condition can lead to confusion, immobility and a fluid build-up in the lungs.
But for those with pre-existing conditions, avoiding altitude sickness requires even more care and planning.
High altitude and pre-existing conditions
Most people can enjoy travelling to areas of higher altitudes if the necessary care is taken, but travellers with certain medical conditions should seek out medical advice before travelling to make sure their condition is stable, and won’t be worsened by the altitude change.
These conditions include:
Heart conditions like high blood pressure and heart disease
Lung conditions like asthma and chronic obstructive pulmonary disease (COPD)
Sick cell disease
Pregnancy also requires greater care in higher altitudes, as the World Health Organisation recommended avoiding altitudes higher than 3000m when pregnant.
Age and disability can also impact the risk of altitude sickness when travelling, so be sure to consult your GP if you feel your chances of developing the condition may be higher.
Precautions against altitude sickness
No matter who you are and how robust your overall health is, it is vital that you take precautions when travelling to high altitudes.
It is generally advised that you avoid travelling from altitudes less than 1,200m to altitudes greater than 3,500m in a single day. When you reach altitudes higher than 3,000m, avoid increasing your elevation by more than 500m a day, and make room for a rest day every three or four days.
If you do begin to develop symptoms of high altitude, don’t continue to ascend. Always attempt to descend if your symptoms worsen or become severe.
Medications like acetazolamide can be used to lessen the impact of altitude sickness, aiding recovery, by causing a mild metabolic acidosis which increases respiratory rate, improving oxygenation.
You can find safe and effective altitude sickness treatment like acetazolamide right here at Express Pharmacy. Get in touch with our pharmacists today by calling 0208 123 07 03 or by using our discreet online Live Chat service.
 Hackett, PR. Roach, RC. High altitude medicine in: Wilderness Medicine. 2011
 Palmer, BF. Physiology and pathophysiology with ascent to altitude. American Journal of Medical Science. 2010
 Charlton, T. PhD. Altitude sickness — a doctor’s story. Bupa UK. 2018
 Cleveland Clinic. Altitude Sickness. 2017
 NHS Fit for Travel. Altitude and Travel. 2018
 World Health Organisation. International Travel and Health: Travellers with pre-existing medical conditions and special needs. 2019
 Travel Health Pro. Altitude sickness. 2018
 Luks, AM. Et al. Wilderness Medical Society practice guidelines for the prevention and treatment of acute altitude illness. Wilderness Environ Med. 2014
 Williamson, J. et al. Altitude sickness and acetazolamide. BMJ. 2018