Acute Mountain Sickness (AMS) is a physical reaction that occurs when a person ascends too quickly to a high elevation where available oxygen is significantly reduced. Symptoms usually begin above 8,000 feet (2,500 meters) and can range from mild discomfort to severe illness. Over-the-counter (OTC) options manage milder symptoms and provide supportive care while the body adjusts, a process known as acclimatization. This information is for general guidance and is not a replacement for professional medical consultation, especially if you have pre-existing conditions or are planning a rapid ascent.
Recognizing the Symptoms
Mild altitude sickness presents with non-specific symptoms that can be mistaken for a bad cold, exhaustion, or a hangover. The most common symptom is a throbbing headache, which is often made worse by exertion. Individuals frequently experience digestive upset, including nausea, sometimes vomiting, and a loss of appetite.
Fatigue, weakness, and dizziness are frequently reported after a rapid ascent. Difficulty sleeping, known as periodic breathing, is a sign of the body struggling to adjust to lower oxygen levels at night. These symptoms typically start within six to twelve hours of arrival and usually resolve within a day or two with rest and supportive measures.
Over-the-Counter Medication Options
The goal of non-prescription medications is to alleviate specific symptoms of mild AMS, allowing the individual to rest and acclimatize. For managing the altitude headache, nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen or acetaminophen are the first-line options. Ibuprofen, typically taken as 600 milligrams every eight hours, is beneficial because its anti-inflammatory properties may help reduce the swelling contributing to the headache.
Acetaminophen, a pain reliever without anti-inflammatory action, is also effective for headache relief and can be taken at standard doses. For nausea, OTC anti-nausea medications like dimenhydrinate (Dramamine) or bismuth subsalicylate (Pepto-Bismol) can help settle the stomach. Anti-nausea medications sometimes cause drowsiness, which should be considered if planning activity.
These OTC options manage symptoms but do not speed up the acclimatization process itself. Effective prevention often relies on prescription medications, such as acetazolamide (Diamox), which must be obtained from a doctor prior to travel. While some studies suggested ibuprofen could be used preventatively, research indicates it is less effective than prescription options for prophylaxis during a rapid ascent.
Non-Medication Supportive Measures
Acclimatization is the body’s natural defense against altitude sickness, and non-medication strategies support this process. Staying well-hydrated is paramount, as dehydration can mimic or worsen AMS symptoms, requiring generous fluid intake. Avoid substances that promote fluid loss, such as alcohol and excessive caffeine, especially during the first 48 hours at altitude.
Dietary choices also play a role; high-carbohydrate meals are recommended because the body uses carbohydrates more efficiently than fats or proteins in a low-oxygen environment. A slow and gradual ascent is the most effective preventative measure. Limit your daily vertical gain and take rest days for every few thousand feet of elevation gained. If symptoms develop, stop ascending immediately and rest until they disappear.
Some individuals utilize herbal supplements, such as Ginkgo Biloba, for altitude support. However, scientific evidence regarding its effectiveness for preventing AMS remains mixed and inconclusive, with some studies showing no benefit. Supplements should only be considered a supportive measure and not a substitute for proper acclimatization or symptom management with proven medications.
Knowing When to Seek Professional Help
While most cases of AMS are mild and resolve quickly, recognize when symptoms signal a progression to a severe, life-threatening altitude illness. Severe symptoms require immediate descent and urgent medical attention, as they indicate dangerous fluid accumulation in the brain or lungs.
Signs of High Altitude Cerebral Edema (HACE) include severe confusion, a change in mental status, or a loss of coordination, often tested by an inability to walk a straight line. Symptoms of High Altitude Pulmonary Edema (HAPE) involve a persistent, hacking cough, severe shortness of breath at rest, and chest tightness. If any of these signs appear, immediate descent to a lower altitude is the most important action.