High elevation headache: what to know

High elevation headache can develop after climbing quickly because thinner air, lower oxygen and fluid loss strain the body. It often begins after reaching a higher altitude and may improve after rest, fluids and stopping further ascent. A headache can also have an unrelated cause, such as a viral illness, sinus symptoms, heat exposure or dehydration.

Altitude-related illness becomes more concerning when headache is joined by nausea, unusual tiredness, dizziness or poor coordination. Symptoms may worsen if you continue climbing or sleep at a higher level. Congestion, facial pressure or a sore throat can point toward Allergic Rhinitis, Chronic Sinusitis or a Common Cold instead. Fever, body aches or exposure to infection may suggest COVID-19. Do not assume every high-altitude headache is caused by altitude.

Stop ascending and rest in a safe place. Sip fluids regularly and avoid alcohol. Keep warm, reduce exertion and tell someone how you feel. If symptoms do not settle or they worsen, move to a lower elevation with help; do not travel alone when confused or unsteady. A clinician can advise whether a medicine is suitable for you, especially if you have other conditions or take regular medicines.

Get urgent medical help for confusion, fainting, trouble walking, severe breathlessness at rest, blue lips, repeated vomiting, chest tightness or a rapidly worsening headache. Seek prompt assessment if the headache continues despite stopping ascent and resting, or if you also have marked thirst, very little urine, overheating or weakness, which can occur with Dehydration or Heat Exhaustion. If fever or a severe illness develops, seek care rather than attributing it to altitude.

Ask: Could altitude explain the timing and pattern of my headache? Should I descend or avoid further ascent? Which pain relief is appropriate with my health history? What symptoms should make me seek emergency help? Could congestion, infection or dehydration be contributing?