While changes in cerebral blood flow are said to be the cause of altitude sickness, Professor Kazunobu Okazaki of the Urban Health and Sports Research Center at Osaka Metropolitan University, Professor Emeritus Katsumi Asano of the University of Tsukuba, and Professor Masahiro Horiuchi of the Department of Sports and Life Sciences at Kanoya National Institute of Fitness and Sports investigated the blood flow and diameter of the internal carotid and vertebral arteries in healthy men at the summit of Mt. Fuji and found that an increase in blood flow and diameter of the internal carotid artery was related to headaches.
The research group investigated the relationship between blood flow in the internal carotid and vertebral arteries, blood vessel diameter, and headaches in eight healthy men at the Fuji Weather Station located at the summit of Mount Fuji, which is 3,776 meters above sea level.
According to the study, during a three-day stay at a weather station, the blood flow and diameter of the internal carotid arteries of eight men increased with the length of their stay, and the severity of their headaches increased accordingly. The relationship between changes in blood flow and headaches was particularly pronounced, and the research group believes that the increase in blood flow is the cause of altitude sickness.
When climbing high mountains, people can develop altitude sickness, which can cause headaches, nausea, dizziness, and fatigue. It has been said that headaches occur due to increased blood flow to the brain, but there have been no studies that have actually measured brain blood flow at high altitudes.
The research group will continue to study the relationship between increased blood flow and headaches, aiming to gather insights that will be useful for preventing and early intervention in altitude sickness. However, these findings may also be helpful in understanding other headache disorders, such as migraines.
