What is Altitude Sickness?
Acute Mountain Sickness (AMS) is your body's response to the lower oxygen levels and reduced air pressure found at high elevations, typically above 8,000 feet (about 2,500 metres). As you ascend, your body needs time to adjust, a process called acclimatisation.
If you climb too high too fast, you can develop symptoms like headaches, nausea, dizziness, fatigue, and difficulty sleeping. These are not just minor inconveniences; they are warning signs from your body that it is struggling to cope with the altitude. Ignoring them can lead to more severe and life-threatening conditions. November travel, while beautiful, doesn't change this risk.
The Primary Medication: Acetazolamide
The most common and recommended preventive medication for altitude sickness is Acetazolamide, often sold under the brand name Diamox. It's a prescription drug that helps your body acclimatise faster. It works by increasing the amount of acid in your blood, which in turn stimulates your breathing. This increased respiration helps you take in more oxygen, counteracting the effects of the thin mountain air, especially at night when breathing naturally slows down. It doesn't mask symptoms; rather, it fundamentally helps your body adjust to the hypoxic environment.
Proper Usage and Timing
Timing is crucial for Acetazolamide to be effective. It should be taken as a preventive measure, not as a last-minute cure. The standard medical advice is to start taking the medication 24 to 48 hours before you begin your ascent to a high altitude. You should continue taking it for the first 48 hours you are at your highest altitude, or as prescribed by your doctor. A typical dosage might be 125mg twice a day, but this can vary. It's essential to follow the specific instructions from your healthcare provider, as they will tailor the dose to your itinerary and health profile.
Understanding Potential Side Effects
While effective, Acetazolamide has common side effects that you should be aware of so they don't cause alarm. The most frequent is a tingling sensation in the hands, feet, or face. Because it is a diuretic, you will likely need to urinate more often, making hydration even more critical. Some people also experience a change in how carbonated drinks taste. Less common but more serious side effects can include nausea, fatigue, and confusion, which can mimic altitude sickness itself. If you experience severe reactions, consult your medical guide or descend.
Medication is Not a Magic Bullet
Relying solely on medication is a dangerous mistake. The most effective way to prevent altitude sickness is through proper acclimatisation. This means ascending slowly, ideally no more than 1,000 to 1,500 feet of sleeping altitude per day once above 10,000 feet. Build rest days into your itinerary. Staying well-hydrated by drinking plenty of water is essential, as dehydration is common at altitude. You should also eat plenty of carbohydrates for energy and avoid alcohol, smoking, and sleeping pills, which can worsen symptoms and complicate your body's acclimatisation process.
Other Medications and When to Descend
Another medication, Dexamethasone, is a steroid used to prevent and treat AMS. However, it is generally reserved for situations where Acetazolamide cannot be taken or for treating moderate to severe AMS, as it can mask symptoms without aiding acclimatisation. The golden rule of high-altitude trekking remains: if your symptoms are moderate and not improving, or if they are severe (such as loss of coordination, severe headache, or a wet cough), you must descend immediately. A descent of just 500-1000 metres can bring significant relief and is the most reliable treatment for serious AMS.
