What are high altitude headaches (HAH)
Acute ascent to an altitude above 2500 m can produce acute mountain sickness with a bilateral headache of mild or moderate intensity in up to 87%.
It can be associated with nausea, photophobia, vertigo, poor concentration, and, in severe cases, impaired judgment.
It resolves within 24 hours after descent to below 2500 m. High altitude is also a common migraine trigger.
How can High altitude headaches be treated and the risk reduced?
The risk of HAH can be reduced with the use of aspirin 320 mg taken three times at 4-hour intervals starting 1 hour before ascent or ibuprofen 600 mg three times a day starting 6 hours before ascent to an altitude between 3480 m and 4920 m, four doses total.
Acetazolamide 125 mg every 12 hours starting 1 day prior to ascent and continued for 2 to 3 days at maximum altitude may also be effective.
Slow ascent, copious fluid intake, avoidance of alcohol, and 2 days of acclimatization prior to strenuous exercise at high altitude may help to prevent HAH.
HAH can be treated with acetaminophen, ibuprofen, and antiemetics.
Acetazolamide 125 to 250 mg bid or, as an alternative, dexamethasone 2 to 4 mg every 6 hours can be continued for 24 hours after symptoms either resolve or descent is complete.
However, dexamethasone should be used for no longer than 7 days total.