Living at or traveling to high altitudes can raise a person's blood pressure, depending on the rate of ascent and the amount of time spent at the high altitude. The International Society of Mountain Medicine describes high altitude as 5,000 to 11,500 feet above sea level. At higher altitudes, the body works harder to process oxygen. This stress can cause high blood pressure. But the more time a person spends at the higher altitude, the better acclimatized the body becomes.
Hypoxia
Acute mountain sickness is a condition that can affect mountain climbers or anyone traveling at high altitudes. If a person ascends too quickly, hypoxia, or oxygen deprivation, may result. The oxygen deprivation causes blood vessels to constrict, raising blood pressure and causing fluid to leak into the lungs. The condition can be treated with oxygen inhalation and high blood pressure medication. Nearly 20 percent of climbers experience symptoms of acute mountain sickness at 6,300 to 9,700 feet, notes MedlinePlus. Without treatment and descent, the condition can become life-threatening.
Hypertension
Prolonged exposure to high altitudes can have a positive effect on hypertension, or high blood pressure. In his book "Medicine for Mountaineering: And Other Wilderness Activities," Dr. James Wilkerson writes that extended exposure to high altitudes may inhibit the progression of hypertension in some hypertensive individuals. Dr. Wilkerson also notes that many non-hypertensive individuals experienced the opposite effect--an increase in their blood pressure rates when exposed to high altitudes.
Systolic Pressure
In the November 2009 issue of the "Journal of Travel Medicine," Dr. Timothy O'Brien writes that black mountain climbers study volunteers experienced a drop in their systolic pressure numbers as they ascended a mountain. Systolic pressure is the amount of force placed against the body's arterial walls when the heart contracts. It is designated by the top number in a blood pressure reading. Dr. O'Brien's also notes that the systolic pressure of white mountain climbers increased as they ascended. The cause of the racial differences is unknown, but Dr. O'Brien suggests it may be due to differences in genetics, hypoxic stress, diet and exercise.
References
- International Society of Mountain Medicine: An Altitude Tutorial
- Medline Plus: Acute Mountain Sickness
- "Medicine for Mountaineering: And Other Wilderness Activities"; James A. Wilkerson, M.D.; 2001
- "Journal of Travel Medicine"; Journeys to High Altitude: Risks and Recommendations; Timothy O'Brien, M.D., Ph.D.; November 2009
