Trekking to Altitude? A Medway Traveller's Guide to Altitude Sickness and Diamox
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Quick answer
Altitude sickness (acute mountain sickness) can affect anyone above roughly 2,500 metres, no matter how fit they are. The most reliable protection is a slow, staged ascent that lets your body acclimatise. Acetazolamide (Diamox) can lower the risk on faster climbs and may be prescribed after a consultation. If symptoms get worse, especially confusion, breathlessness at rest, or an unsteady walk, the only dependable treatment is to go down. Medway Pharmacy can advise and supply Diamox before you travel.
What altitude sickness is, and who gets it
As you climb higher, the air thins and each breath delivers less oxygen. Given time, your body adjusts, but if you go up faster than it can adapt, you can develop altitude sickness. It usually begins above about 2,500 metres and the first symptoms tend to appear 6 to 24 hours after arriving at a new height.
One of the most important things to understand is that being young, fit or experienced does not protect you. Elite athletes get altitude sickness just as recreational trekkers do. How your body responds is largely down to your individual physiology and, above all, how quickly you ascend.
The three forms, from mild to life-threatening
Acute mountain sickness (AMS) is the common, milder form. It feels like a hangover: headache, loss of appetite, nausea, tiredness, dizziness and poor sleep. It is a clear signal to stop going higher until you feel better.
High-altitude cerebral oedema (HACE) is a dangerous swelling of the brain. Warning signs include confusion, clumsiness, an unsteady “drunken” walk, and drowsiness. It is a medical emergency.
High-altitude pulmonary oedema (HAPE) is a build-up of fluid in the lungs. Signs include breathlessness even at rest, a persistent cough that may bring up frothy or pink spit, and extreme fatigue. It, too, is an emergency.
HACE and HAPE can be fatal within hours if ignored. If you or a companion develop confusion, an unsteady walk, or breathlessness at rest, treat it as an emergency: descend without delay and seek help. Never leave someone with these symptoms alone, and never let them continue upward.
The golden rules of acclimatisation
The single best way to prevent altitude sickness costs nothing: go up slowly. A well-planned itinerary builds in time to adjust.
- Ascend gradually. Once above 3,000 metres, try not to increase your sleeping altitude by more than about 300 to 500 metres per night.
- Climb high, sleep low. Walking to a higher point during the day and returning lower to sleep helps your body adapt.
- Build in rest days. A day at the same altitude every few days gives your body time to catch up.
- Stay hydrated and skip the alcohol for the first few days at altitude, and avoid sleeping tablets, which can suppress breathing.
- Never ascend with symptoms. If you have any signs of AMS, wait where you are until they clear before going higher.
Where UK travellers meet altitude
You do not have to be a mountaineer to reach heights where this matters. Popular trips that take travellers well above 2,500 metres include Kilimanjaro in Tanzania (5,895 metres), the Everest Base Camp trek in Nepal, and Peru, where Cusco and Machu Picchu sit around 3,400 metres and many people fly straight in. Others include the Bolivian altiplano and La Paz, Ladakh in India, and parts of the Andes and Atlas mountains. Flying directly to a high city gives your body no time to adjust, so plan a gentler start where you can.
Where acetazolamide (Diamox) fits in
Acetazolamide, better known by the brand name Diamox, is a prescription medicine that helps your body acclimatise more quickly. It is useful when a slow ascent is not possible, for example if you have to fly straight to a high-altitude city, or for people who have had altitude sickness before.
A typical preventive dose is 125 mg twice a day, started the day before you begin to ascend and continued for the first two to three days at your target altitude. Some people notice tingling in the fingers, more frequent urination, or that fizzy drinks taste odd: these effects are harmless. It is related to sulfonamide medicines, so tell the pharmacist if you have a sulfa allergy. Importantly, Diamox reduces the risk of altitude sickness but does not remove it, and it is never a substitute for descending if you become unwell.
If symptoms develop: the one rule that matters
Mild AMS often settles if you stop climbing, rest, drink fluids and take simple painkillers for the headache. Do not go any higher until you feel completely well. If symptoms are getting worse, or you notice any sign of HACE or HAPE, the treatment is to descend, typically by 300 to 1,000 metres, as soon as it is safe to do so. Going down even a few hundred metres can bring rapid improvement, and it should never be delayed for the sake of reaching a summit.
Before you fly
Give yourself a proper pre-trip check. Make sure your travel insurance covers trekking at the altitudes on your itinerary and any emergency evacuation. Pack a small kit with painkillers and rehydration sachets, and talk to a travel health professional about whether Diamox is appropriate for you, especially if you have a heart, lung or kidney condition, or take other medicines.
Book altitude advice in Medway
Book a travel health appointment at 465 Canterbury Street, Gillingham, ME7 5LJ. Our pharmacists can review your trekking plans, advise on acetazolamide (Diamox) and check any vaccines you need for the same destination. Open 7 days a week until 10pm, with same-day appointments. Call 01634 575805.
Frequently asked questions
No. Fitness has little bearing on who gets altitude sickness. In fact, fit people sometimes get into trouble because they ascend quickly and push on through early symptoms. Everyone should ascend gradually and respect the warning signs, regardless of how strong they feel.
Acetazolamide is a prescription medicine, so it needs a short consultation first. At Medway Pharmacy we can assess your itinerary and medical history and, where appropriate, supply Diamox with clear instructions on how and when to take it. It is best to sort this out a week or two before you fly.
The usual approach is to begin the day before you start ascending and to continue for the first two to three days at your highest altitude, or until you have acclimatised. Your pharmacist will give you a plan tailored to your trip. If you develop symptoms despite taking it, the priority is still to stop ascending and, if needed, descend.
Children can get altitude sickness too, and it can be harder to spot in a young child who cannot describe how they feel. People with heart, lung or other chronic conditions should get individual advice before a high-altitude trip. Bring a list of your medicines to your appointment so we can check for interactions and give safe, personalised advice.
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