Travelling to high-altitude destinations can be one of life’s most rewarding experiences, but for many, it also brings an unexpected challenge: altitude sickness. If you’ve ever arrived in the mountains and suddenly developed a throbbing headache, dizziness, or nausea, you may have experienced acute mountain sickness (AMS)—the body’s natural reaction to a rapid increase in altitude.

At Vivo Pharmacy and Travel Clinic, we regularly advise travellers preparing for high-altitude trips. One of the most common questions we hear is whether altitude sickness tablets are necessary and how they work.

In this guide, we’ll explain the symptoms of AMS, when to consider medication, and how these tablets can help reduce discomfort and risk as you explore the heights of the world.

Understanding Acute Mountain Sickness (AMS)

Acute mountain sickness occurs when the body struggles to adapt to lower oxygen levels at elevations typically above 2,500 metres (approximately 8,200 feet). The higher you go, the thinner the air becomes, making it harder for your body to get the oxygen it needs.

Symptoms of AMS can develop within hours of ascent and range from mild to severe. The most common early signs include headache, fatigue, dizziness, shortness of breath, nausea, and difficulty sleeping. In more serious cases, altitude sickness can progress into high-altitude pulmonary oedema (HAPE) or high-altitude cerebral oedema (HACE), both of which require urgent medical attention.

While anyone can develop AMS, even if they’re fit and healthy, certain factors increase your risk. These include ascending too quickly, a previous history of altitude sickness, dehydration, and engaging in strenuous activity soon after arrival.

When Should You Consider Altitude Sickness Tablets?

If you’re planning to travel to an area above 2,500 metres—such as Cusco or Machu Picchu in Peru, the Himalayas in Nepal, Mount Kilimanjaro in Tanzania, or the high-altitude regions of Colorado in the United States—it’s worth speaking to a travel health professional about prevention.

Altitude sickness tablets are often recommended for:

• –> Travellers ascending rapidly (e.g. by plane or vehicle without acclimatisation)

• –> Trekkers or climbers sleeping above 3,000 metres

• –> People with previous experience of AMS

• –> Those with tight itineraries where gradual ascent isn’t possible

• –> Individuals on guided tours or in remote locations with limited access to emergency care

Taking preventive medication can reduce the chances of developing symptoms and may improve comfort and safety during your trip.

How Do Altitude Sickness Tablets Work?

The most commonly prescribed medication for preventing altitude sickness is acetazolamide (often known by the brand name Diamox). This medication helps your body adjust to high altitude more efficiently by stimulating breathing and balancing the pH levels of your blood. In simple terms, it encourages your system to take in more oxygen and excrete bicarbonate, which speeds up acclimatisation.

When taken as directed, acetazolamide can:

• –> Reduce the likelihood of developing AMS

• –> Lessen the severity of symptoms if they do occur

• –> Improve sleep quality at altitude

• –> Allow for a safer and more enjoyable ascent

Acetazolamide is typically started one to two days before ascending and continued for several days after reaching high altitude. Your dose and duration will depend on your travel plans and medical history, which is why we always recommend a personalised consultation before starting treatment.

Other medications sometimes used include ibuprofen or paracetamol (for headache relief), or anti-sickness tablets to ease nausea, but these only treat symptoms once they begin. Acetazolamide remains the most effective option for true prevention.

Who Might Need Altitude Sickness Tablets the Most?

While any traveller heading to altitude could benefit, certain groups should take particular care.

If you’re planning a trek in the Andes, Himalayas, or African mountain ranges where quick ascents are common, altitude sickness tablets are often advised. Group treks and short climbing expeditions with tight turnaround times allow little opportunity for natural acclimatisation, increasing your risk.

Business travellers flying directly to high-altitude cities for meetings or conferences may also need medication, particularly if they’re not staying long enough for their bodies to adjust naturally.

Older adults or individuals with underlying health conditions, such as heart or lung disease, should consult a healthcare professional before travelling, as the effects of low oxygen can be more pronounced.

Why It’s Worth Planning Ahead

Even mild AMS can leave you feeling drained, irritable, and unable to enjoy your experience. Severe symptoms can derail an entire trip or require descent to lower altitude. By preparing with the right advice and access to altitude sickness tablets, you give yourself the best chance of staying healthy and enjoying your travels to the fullest.

At Vivo Pharmacy, our travel health consultations ensure you receive tailored advice based on your destination, medical history, and itinerary. We can prescribe and dispense altitude sickness tablets such as acetazolamide, along with other essential medications and preventative guidance for your journey.

Book Your Travel Consultation with Vivo Pharmacy

If you’re heading to high altitudes and want to avoid the discomfort or risk of altitude sickness, get in touch with our friendly team at Vivo Pharmacy & Health Clinic. We’ll help you prepare with the right medication, advice, and support, so you can focus on enjoying the view.

Book your travel consultation today and get the guidance you need for a safe and healthy journey at altitude.

This blog was written on behalf of Vivo Pharmacy by Pharmacy Mentor.