Oxygen therapy for altitude sickness

Oxygen is especially valuable when descent is delayed or a person has signs of brain or lung involvement. It is a bridge to safer conditions, not proof that the illness has resolved. Symptoms can return when oxygen stops if the person remains at the same elevation.

At high elevation, lower air pressure reduces the oxygen available with each breath. Supplemental oxygen raises the amount reaching the lungs and bloodstream, which can improve breathing, alertness, and tissue oxygenation. The delivery method and flow depend on the equipment, the person's condition, and clinical guidance.

A pulse oximeter may support monitoring, but a single reading cannot grade illness or rule it out. Cold hands, movement, device quality, and elevation affect the result. Changes in breathing, coordination, behaviour, and ability to walk remain crucial observations.

Follow the equipment instructions and any plan provided by a qualified clinician or expedition medical lead. Check the supply, mask fit, regulator, spare parts, and expected access to refills before travel. Keep cylinders away from flames, smoking, oil, grease, and unsecured transport.

While oxygen is being given, stop ascent, keep the person warm, limit exertion, and arrange descent. Watch whether alertness, walking, breathing, and symptoms improve. Never send an unwell person down alone. If oxygen runs low, prioritise evacuation rather than rationing it to preserve the itinerary.

Confusion, marked drowsiness, poor coordination, collapse, breathlessness at rest, blue or grey lips, chest tightness, or a wet cough suggests serious altitude illness. Start emergency descent when safe, call for medical help, give oxygen if available, and minimise the person's effort.

Seek urgent assessment if improvement is incomplete, symptoms return when oxygen is removed, or another cause such as asthma, infection, a blood clot, or a heart problem is possible. A normal-looking oximeter value after oxygen does not cancel concerning symptoms.

Ask whether your health or route makes supplemental oxygen appropriate, what device fits the setting, who will be trained to operate it, and how much evacuation time the plan must cover. People with existing heart or lung disease, sleep-related breathing problems, or home oxygen needs should obtain individual advice before travelling high.