Altitude Sickness - Treatment and Prevention
Altitude sickness can hit US travelers fast at high elevations, but with the right prevention plan and medication, you can enjoy your trip safely.
Altitude sickness prevention for travelers
Altitude sickness, also called acute mountain sickness (AMS), happens when your body does not get enough oxygen at high elevations. It can affect any traveler who ascends quickly to high altitudes, regardless of age or fitness level. US travelers heading to destinations like the Andes, the Himalayas, or other high-elevation regions need to plan ahead, because symptoms can start within hours of arrival.
WayPax Health is a full virtual travel clinic. A licensed provider will review your itinerary and can issue a real prescription for preventive medication without you ever setting foot in a clinic.
Get your Altitude Sickness prescription and other travel medicines online today.How to prevent altitude sickness
The most effective way to prevent altitude sickness is to ascend slowly and give your body time to adjust. According to NIH guidelines, travelers should plan no more than one day of travel for every 1,500 feet gained above 10,000 feet, with a rest day every three to four days. This gradual approach, called acclimatization, lets your body adapt to lower oxygen levels before going higher.
For travelers who cannot ascend gradually due to their itinerary, prescription medication is the most reliable prevention option. Acetazolamide is the preferred preventive drug for altitude sickness. Research published by NIH confirms that acetazolamide is effective at preventing AMS symptoms. It works by helping your body breathe faster and adjust to altitude more quickly. Dexamethasone is a second-line option for travelers who cannot take acetazolamide. Per NIH's StatPearls, acetazolamide is the preferred choice for both prevention and treatment. Ibuprofen may also help reduce altitude headache. Travelers should talk to a provider about which option is right for them, as dosing and timing depend on individual health history and trip details.
WayPax Health recommendation
WayPax Health stocks an Altitude Sickness Kit that includes acetazolamide as the first-line preventive medication, along with dexamethasone 4 mg as a second-line option for travelers who have a sulfa allergy or cannot take acetazolamide. This kit is especially important for adventure travelers, trekkers, and anyone planning a rapid ascent to high-elevation destinations such as the Andes or the Himalayas. A WayPax provider can review your full itinerary, discuss your health history, and write a real prescription for preventive medication entirely online, with no clinic visit required. This is the same level of personalized travel health care you would get at a traditional travel clinic, done from your home. Getting your prescription through WayPax before your trip means you arrive prepared and confident, with the right medications already in hand.
Get your Altitude Sickness prescription and other travel medicines online today.
What is altitude sickness?
Altitude sickness is a condition caused by low oxygen levels at high elevations, a state called hypobaric hypoxia (meaning less oxygen pressure in the air). It is not caused by a virus or bacteria, so it cannot be caught from another person. It happens when you ascend to high altitude faster than your body can adjust. According to the CDC, symptoms typically begin within six to twelve hours of arriving at altitude.
The most common symptoms of altitude sickness include headache, fatigue, dizziness, nausea, and difficulty sleeping. These are signs of mild AMS. If the condition gets worse, it can progress to more serious forms: high-altitude pulmonary edema (HAPE, meaning fluid in the lungs) or high-altitude cerebral edema (HACE, meaning swelling of the brain). As noted in NIH's high-altitude travel reference, these severe forms are medical emergencies. NIH research on high-altitude medicine confirms that anyone who ascends rapidly to altitudes above 3,000 meters (about 9,800 feet) is at risk, regardless of fitness level or prior experience at altitude.
Where is altitude sickness a risk?
Altitude sickness is a risk anywhere travelers ascend rapidly to high elevations. The risk is not tied to a specific country or climate but to the elevation itself and the speed of ascent. The CDC notes that symptoms can occur at elevations above roughly 8,000 feet (2,500 meters), and the risk increases significantly above 10,000 feet (3,000 meters).
High-risk regions include the high mountain ranges of South America, particularly the Andean plateau that stretches across parts of the continent, where several major cities and popular trekking routes sit at extreme elevations. The Himalayan region of South and Central Asia is another area of very high risk, drawing trekkers and climbers who often ascend quickly. Parts of East Africa also present risk, particularly for travelers attempting high-elevation climbs. High-altitude destinations in Central Asia and parts of the Middle East can also pose a risk depending on the traveler's itinerary and ascent rate.
Seasonal conditions can influence risk as well. Cold temperatures at altitude can make symptoms feel worse, and some routes are only accessible during certain seasons, which may push travelers toward faster ascent schedules. The key factor in all regions is always the rate of ascent, not the destination itself.
Treatment: what to do if you get altitude sickness
If you develop symptoms of altitude sickness, the most important first step is to stop ascending. Do not go higher until symptoms fully resolve. In many mild cases, resting at the same elevation for a day or two allows the body to adjust and symptoms to improve on their own.
If symptoms do not improve or get worse, descending to a lower elevation is the most effective treatment. Per NIH's StatPearls, acetazolamide can also be used to treat mild to moderate AMS, and dexamethasone is used for more severe cases or when descent is not immediately possible. Ibuprofen and acetaminophen can help relieve headache pain.
Seek emergency medical care immediately if you experience confusion, loss of coordination, severe shortness of breath at rest, or a persistent cough with pink or frothy mucus. These are warning signs of HAPE or HACE, both of which are life-threatening and require urgent descent and medical treatment.
Frequently asked questions
What are the symptoms of altitude sickness in travelers?
The most common symptoms are headache, fatigue, dizziness, nausea, and poor sleep. These usually begin within six to twelve hours of arriving at high altitude. If symptoms worsen and include confusion, loss of balance, or severe shortness of breath, this may signal a dangerous progression and requires immediate descent and medical attention.
How can I prevent altitude sickness when traveling?
The best prevention is a slow, gradual ascent that gives your body time to adjust to lower oxygen levels. If your itinerary does not allow for a slow ascent, prescription medication such as acetazolamide can significantly reduce your risk. Talk to a travel health provider before your trip to find out which prevention strategy is right for you.
Can you get altitude sickness at high altitude even if you are fit and healthy?
Yes. Fitness level does not protect you from altitude sickness. Anyone who ascends too quickly can develop symptoms, regardless of age, physical condition, or prior experience at altitude. The only reliable protection is a slow ascent or preventive medication prescribed by a provider.
How is altitude sickness treated while traveling?
Mild cases often improve with rest at the same elevation. If symptoms do not get better, descending to a lower elevation is the most effective treatment. Prescription medications such as acetazolamide and dexamethasone can also help. Travelers should seek emergency care right away if they experience confusion, severe shortness of breath, or loss of coordination.
Should I worry about altitude sickness when flying to high places?
Yes, flying directly to a high-altitude destination is one of the fastest ways to trigger altitude sickness because your body has no time to adjust. Travelers who fly into cities or airports at high elevations should plan rest days upon arrival and consider speaking with a provider about preventive medication before departure.
When does altitude sickness usually start?
Symptoms typically begin within six to twelve hours of arriving at altitude. In some cases, they can appear sooner, especially after a very rapid ascent. Symptoms often feel worse at night and may improve slightly during the day, but they should not be ignored if they persist or worsen.
Where can I get a prescription for altitude sickness medication before my trip?
WayPax Health is a full virtual travel clinic where you can get a real prescription for altitude sickness prevention medication entirely online. A licensed provider will review your itinerary and health history and can prescribe acetazolamide or dexamethasone without you needing to visit a clinic in person. You can get started right away at WayPax and have your prescription ready well before your departure date.
Explore by region
South America
South and Central Asia
Central Asia
Middle East and North Africa
East Africa
Related diseases
- High-altitude pulmonary edema (HAPE), a severe complication of altitude illness
- High-altitude cerebral edema (HACE), a severe complication of altitude illness
- Malaria, a risk in many of the same low-elevation regions travelers pass through on the way to high-altitude destinations
- Travelers' diarrhea, common in the same adventure travel destinations where altitude sickness risk is high
- Motion sickness, which can occur alongside altitude symptoms during mountain travel by road or air
A WayPax provider can build a Trip Kit for your specific itinerary — prescriptions, destination guidance, and a Customs Declaration Letter, ready before you board.
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