Causes of Asthma

Quincy AdamAsthma Learn

The causes of asthma are not fully known, but research indicates that they are likely brought on by a combination of genetic and environmental factors.

However, someone can have a genetic predisposition to asthma and yet never exhibit symptoms. Triggers that provoke asthma symptoms must also be present in order for the disease to evolve. The more severe the triggers are—especially in early childhood, when the immune system is developing—the higher the risk of developing asthma.

It’s important to examine the causes of asthma symptoms—many of which are easy to control and reduce. There are both allergenic and non-allergenic triggers for asthma. Allergenic response in the asthma sufferer, regardless of the trigger, always results in increased bronchial reactivity.

Common allergenic triggers are:

  • Pollen
  • Mold spores
  • Pet dander and secretions
  • Cockroach antigens
  • Dust mites (especially exposure in the first year of life)
  • Certain foods
  • Fungi

“Our analysis found that there are large numbers of fungi present in healthy human lungs. The study also demonstrates that asthma patients have a large number of fungi in their lungs and that the species of fungi are quite different to those present in the lungs of healthy individuals”
– Hugo van Woerden from Cardiff University’s Institute of Primary Care and Public Health.1

Even though allergies and asthma are closely related, not everyone with allergies develops asthma, and not all people with asthma have allergies. There are many non-allergenic triggers for asthma. Common non-allergenic triggers are:

  • Tobacco smoke
  • Severe weather (cold, dry, wet, windy)
  • Strong odors
  • Chemical fumes
  • Medications including non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen
  • Exercise
  • Hormonal changes such as those caused by menstruation, pregnancy or taking hormone replacement drugs
  • Obesity with the risk being higher for children who are obese during early childhood

The relation between asthma and second-hand smoke exposure is more complex than a temporary irritation to sensitive airways. Second-hand smoke exposure in the home can contribute to a child’s developing asthma in the first place. Children of parents who smoke cigarettes are more likely to develop asthma than children of parents who do not smoke.” Partners Asthma Center.2

“Obesity is associated significantly with the development of asthma, worsening asthma symptoms, and poor asthma control.” CDC – AsthmaStats.3

  • Food additives and, more rarely, sulfite, a preservative
  • Viral respiratory infections
  • Emotional stress

“In the past it was thought that asthma was mainly an emotional disorder. Today it is known that the basis of bronchial asthma is the hyperirritability of and biochemical abnormality in the cells lining airways. […] …while emotional stress can be a significant triggering factor in asthma, it is not the sole cause.” The Asthma Center Education and Research Fund.4

One of the best ways to manage your asthma is to learn what’s causing it. Take an inventory… your home, your diet, your workplace, etc. Determine what you think may be contributing to your asthma, and do whatever you can to control and even eliminate the triggers.


1“Treating asthma,” Cardiff University News Centre, http://www.cardiff.ac.uk/news/articles/treating-asthma-10342.html.
2“Breath of Fresh Air: Feature Articles, Chapter 30, Cigarette Smoking and Asthma,” Partners® Healthcare, http://www.asthma.partners.org/newfiles/BoFAChapter30.html.
3“AsthmaStats,” Centers for Disease Control and Prevention, http://www.cdc.gov/asthma/asthma_stats/asthma_obesity.htm.
4“Is asthma an ‘emotional disease’?” The Asthma Center, http://www.theasthmacenter.org/index.php/faq/is_asthma_an_emotional_disease/.