High Altitude Sickness

If you are traveling to a destination with an altitude of over 2500m, you will be at risk of altitude sickness, pulmonary oedema or serious central nervous system disorder. These risks are negligible below 2500m, possible between 2500 and 3500m and likely over 3500m. There are no reliable predictors for individuals; potentially all travelers have the same risk. Previous tolerance of high altitudes is the only guide that is reliable. The cause of altitude sickness is a reduced oxygen level in the air.

Symptoms:

1. Headache, loss of appetite, nausea, insomnia, dizziness, swollen ankles, ataxia and apathy.
2. Shortness of breath, reduced exercise tolerance (usually these occur on the second day and indicate fluid building up in the lungs – this is a medical emergency)
3. If untreated, the brain will swell, causing coma

Prevention:

It is important to acclimatise. Above 2500m, ascend slowly. Limit each night’s camp to 300m or less above the previous night’s camp altitude. If you wake with symptoms in category 1 or 2, descend immediately, but not alone. Symptoms can progress rapidly and can be fatal. A decompression bag is often used when descent is not possible (usually with a foot pump – this effectively lowers the altitude by 1000m by increasing the oxygen levels). You should still descend after 1-2 hours in the bag.

What Can You Do To Improve Your Chances?

You can take medication to trick your body into breathing more quickly, hence ‘acclimatising’ the body in advance. This medication is called DIAMOX (Acetazolamide) 250mg; half a tablet in morning and half a tablet at lunchtime, starting 1 day prior and continuing for 3-5 days at altitude. It is inexpensive and will give you an edge on your symptoms (they will occur at a higher altitude than otherwise). Remember, group tours ascend at a set rate, and not all people can cope with the same rate of ascent. Rest days are often incorporated into tours, but they are not really for rest, they are because the ascent rate has been too great. Be careful!

NB: Diamox contains sulfur and a test dose is recommended prior to travel. These are available at our clinic free of charge and if you react to it you will be at our clinic, not on a mountain pass. Our specialists will explain how this works at your appointment.