High-Altitude Sickness

High-altitude sickness, also known as altitude illness, is a condition that can occur when a person ascends to high elevations too quickly, typically above 2,500 meters (8,200 feet). It results from reduced air pressure and lower oxygen availability, which make it harder for the body to supply sufficient oxygen to tissues and organs.

The most common and mild form is acute mountain sickness (AMS). Symptoms often begin within hours of ascent and may include headache, nausea, dizziness, fatigue, shortness of breath with exertion, and difficulty sleeping. While uncomfortable, AMS is usually not dangerous if recognised early and managed appropriately.

More severe forms of altitude illness are less common but potentially life-threatening. High-altitude cerebral edema (HACE) involves swelling of the brain and may cause confusion, loss of coordination, severe headache, and altered consciousness. High-altitude pulmonary edema (HAPE) affects the lungs and can lead to breathlessness at rest, coughing (sometimes with frothy or pink sputum), chest tightness, and rapid deterioration. Both conditions require immediate descent and medical attention.

Prevention is the most effective strategy. Gradual ascent allows the body time to acclimatise by increasing breathing rate and producing more red blood cells. Other preventive measures include limiting physical exertion during the first days at altitude, staying well hydrated, avoiding alcohol, and sleeping at a lower elevation than the highest point reached during the day when possible. In some cases, medications such as acetazolamide may be used under medical guidance.

Treatment depends on severity but generally includes rest, halting further ascent, and descending to a lower altitude if symptoms persist or worsen. Supplemental oxygen can be helpful when available. Prompt recognition and response are critical, as severe altitude illness can progress rapidly.

In summary, high-altitude sickness is a predictable and largely preventable condition. With proper planning, gradual ascent, and attention to early symptoms, most people can travel to high elevations safely.