What is altitude sickness?
Altitude sickness can occur when staying at high altitudes or during a rapid ascent, if people are there
are insufficiently accustomed to. The cause is the low oxygen content of the air, causing
oxygen levels in the blood drop and symptoms may arise. The body needs time
to adapt to the lower oxygen levels (acclimatisation).
The higher the stay or the faster the ascent, the greater the risk of altitude sickness. About the
Generally, severe symptoms only occur above 3,000 metres. The susceptibility to
However, altitude sickness varies from person to person, so complaints can also occur at lower altitudes
performance.
What can you recognise altitude sickness from?
Complaints from altitude sickness usually arise several hours to a day after arrival at major
height. Note that in children, it is more difficult to properly recognise these symptoms. Complaints of mild
altitude sickness are headache, nausea, vomiting, dizziness and/or weakness. Note that headache is
an alarm symptom. Usually the symptoms disappear within a few days provided that
there is no further ascent. Mild altitude sickness can progress to severe altitude sickness:
increasing headache that does not go away with painkillers, increasing vomiting, lethargy,
confusion, balance disorders, severe coughing or shortness of breath that does not go away with
resting. You may become so lethargic that help with eating and dressing is needed. Untreated, you may
altitude sickness lead to fluid in the lungs (high-altitude pulmonary edema, HAPE) and brain
(high-altitude cerebral edema, HACE) possibly resulting in coma or death.
Advice for travellers to high altitude
- Acclimatise first at least 2 nights at medium altitude (1500-2500m)
- If you are flying directly to 3,000 metres or higher, sleep the first few nights if possible
lower or stay at the same level for at least several days before rising further. - Adaptation can be promoted by climbing higher during the day than one sleeps at night (climb
high, sleep low). However, avoid strenuous exercise for the first 2 days at altitude. - Ascend above 3,000 metres no more than 500 metres per overnight stay and take a
rest day. - If more than 500 m is climbed in 1 night anyway, spend at least 2 nights on the same
height by. - Drink enough so that urine remains clear and light-coloured.
- Do not consume alcohol or sleeping pills.
- Make sure you have a flexible itinerary so you can rest for a few days in case of altitude sickness.
- Consult with your doctor if you have sickle cell disease or heart and/or lung disease.
Acetazolamide (Diamox®)
In high-risk cases, an acetazolamide (Diamox®) may be prescribed to reduce the
promote acclimatisation. This remedy may be advised for the prevention of
altitude sickness or as early treatment for symptoms.
- You take the drug to prevent severe altitude sickness (preventative). Start 24 hours before
reaching 3,000 metres. Take ½ tablet in the morning and ½ tablet in the afternoon. Continue
up to 2 days after reaching the highest altitude. - You will take the drug to treat altitude sickness (early treatment). Start with the
remedy, even with mild symptoms, if you will climb even higher after this. Take 1 tablet in the morning
and in the afternoon 1 tablet. Continue for 3 days or shorter if you descend earlier. If, after continuing
climbing symptoms again, you can take another course of treatment.
- Different doses apply for children < 40 kg.
Possible side effects of acetazolamide include: tingling in the extremities, change in
taste, nausea and more frequent and increased urination. Always read the leaflet carefully before use!
What should you do in case of symptoms of altitude sickness?
- Take symptoms of altitude sickness seriously! Even if it means interrupting the trip or not reaching the summit.
Mild altitude sickness: do not rise further, start with acetazolamide. Descend if symptoms
do not improve within a day. For headache, you can use paracetamol, for nausea
an anti-seizure drug. Once the symptoms have passed, you may gently continue to rise.
Severe altitude sickness: descend immediately and seek medical attention (including oxygen and drugs).
Bear in mind that access to medical care is limited when staying in remote areas!
Other tips
- Take enough paracetamol and home medication with you.
- Dry air often causes eye irritation and can make contact lens wear
complicate. It is advisable to bring glasses. - To combat keratitis (snow blindness/glare eyes) due to high UV exposure, a good
Sunglasses needed. - In cold, high-altitude areas, UV exposure is high and a high factor is
sun protection is needed. Keep in mind snow reflection and also protect
underside of chin, nose and ears. - The dry, cold air at altitude can cause migraines, coughs and sore throats.
See also www.lcr.nl
Download the leaflet below!
