According to the Centers for Disease Control and Prevention: one in thirteen people suffer from
asthma—that’s 25 million people in the United States alone, seven million of which are children under the age of
eighteen. 1 With populations in high elevation towns growing each year, more individuals with asthma will be adjusting
to life “up in the clouds.” While asthma sufferers may be at increased risk of developing a high-altitude illness such as
high altitude pulmonary edema (HAPE), is it possible for them to experience any benefits living at or traveling to
higher elevation? Before we dig in, let us examine what Asthma is and its related symptoms.
Asthma is an obstructive lung disease, meaning airflow is limited due to airway narrowing brought on by
inflammation and bronchial hyperactivity. The vast majority of patients with asthma will develop symptoms of
coughing, wheezing, chest tightness, and difficulty breathing before the age of five. When these symptoms present
intermittently, they can be controlled by a short-acting bronchodilator like Albuterol. For those with more persistent
asthma, an inhaled corticosteroid and (or) a long-acting bronchodilator may be needed in addition to
Albuterol. Exercise, cold weather, upper respiratory illness, stress, air pollution, and dust mite allergens are all known
triggers of an acute asthma attack. Is it possible that high altitude can actually minimize the impact of any of these
triggers?
One of the benefits of living at high altitude is consistently breathing the clean alpine air. Significantly lower
levels of house dust mites and air pollutants are found at high elevations; great news for allergic asthma
sufferers. 2 However, if one does not fall into that category, do not worry! A study published in the European
Respiratory Journal in 2012 showed that high altitude has beneficial effects for all asthma-types, especially those
refractory to steroids. Participants in the study had improved asthma control, improved lung function, and fewer sino-
nasal symptoms after 12 weeks at an altitude of 1,600 meters. 3 Given that even those with nonallergic asthma
benefited from high altitude treatment, there has to be something other than low levels of allergens at play. Several
studies have reported increased levels of catecholamines and cortisol in the bloodstream within the first two weeks of
staying at high altitude. 4 These hormones contribute to decreasing both bronchial inflammation and bronchial
reactivity which helps in controlling asthma symptoms. Furthermore, the lower viscosity of the air and lower oxygen
pressure reduce the resistance of airflow with inspiration and expiration, making it easier to breath! 2 Mountain living
may also yield a less stressful lifestyle. 3 Lower stress equals lower levels of the stress hormones that typically elicit an
inflammatory response, thus keeping asthma symptoms in check.
So, who is at risk when climbing to higher elevations? Anyone with asthma that is not well controlled prior to
to traveling to elevations of 1,500 meters and above could be at greater risk for having an asthma exacerbation when
they arrive. 2 However, little research has been done to determine who is more susceptible to Acute Mountain
Sickness (AMS) or more perilous altitude illnesses like HAPE. A group of researchers studying the effects of high
altitude and cold air exposure on airway inflammation in patients with asthma did incidentally find that patients with
lower oxygen saturation levels during a hypoxic exercise test were more likely to suffer from AMS when climbing to
high altitude. 4
What have we learned? HIGH altitude equals a LOW trigger environment for asthma patients. That means
it’s time to take that desired mountain vacation or tell your loved ones that suffer from asthma to finally come visit you
in the mountains! Keep in mind, the cold, dry air often accompanied by high elevations can incite an inflammatory
response, in turn, worsening asthma symptoms for some. We recommend visiting in the summer months. This
adverse reaction to cold air can be thwarted by using a face mask or other protective gear that not only warms but
also humidifies inspired air. 5
Disclaimer: If you or a loved one with asthma plan on traveling to high altitude be sure to check in with your primary
care provider first. If your asthma is not well controlled you may want to avoid any travel as it could increase your risk
of an attack. Be prepared! Always carry your rescue inhaler and if you plan on going up in elevation be extra
cautious and bring inhaled or oral steroids as well.
Laura Greenberg, PAS-II
Midwestern University Physician Assistant Program
Clinical Rotation—September 2017
Resources
- Centers for Disease Control. Asthma. http://www.cdc.gov/asthma/default.htm. (retrieved September 24, 2017)
- Mendenhall, A.M. & Forest, C.P. (2017). Out of air: Is going to high altitude safe for your patient. JAAPA, 30(8), 10-15.
- Rijssenbeek-Nouwens, L.H., Fieten, K.B., Bron, A.O., Hashimoto, S., Bel, E.H., and Weersink, E.J. (2012). High-altitude treatment in atopic and nonatopic patients with severe asthma. Eur Respir J. 40(6): 1374-1380
- Seys, S.F., Daenen, M., Dilissen, E., Thienen, R.V., Bullens, D.M.V., Hespel, P., Dupont, L.J. (2013). Effects of high altitude and cold air exposure on airway inflammation in patients with asthma. Thorax BMJ. 68: 906-913
- Cogo, A., Fiorenzano, G. (2009). Bronchial Asthma: Advice for Patients Traveling to High Altitude. High Alt Med & Biol. 10(2): 117-121
- Vinnikov, D., Khafagy, A., Blanc, P.D., Brimkulov, N., Steinmaus, C. (2016). High-altitude alpine therapy and lung function in asthma: systematic review and meta-analysis. ERJ open research, DOI: 10.1183/23120541.00097-2015.
- Grissom, C.K., Jones, B.E. (2017). Respiratory Health Benefits and Risks of Living at Moderate Altitude. High Alt Med & Biol. 00(00): 1-7
