This headache is especially common in individuals who climb mountains and ski at high altitudes. It may be seen in acute mountain sickness along with other primary symptoms of pulmonary edema and cerebral edema. The headache is seen at high altitudes (above 8,000 feet and with increasing frequency as elevation increases) and is usually associated with low oxygen levels.
The headache is described as generalized and throbbing and is aggravated by exertion, coughing, and lying down. The headache usually appears from 6 to 96 hours after arriving at high altitudes.
On examination, patients may have retinal hemorrhages, papilledema, and confusion. Relief of headache is obtained by descending to lower altitudes. Ergotamine may be effective, but oxygen inhalation is especially effective according to neurologist – Dr Winnie Sharon Lim Khoo