What Causes Asthma?

From pollen, to smoke, to the flu: a range of triggers can cause asthma symptoms.

On this page


Asthma is a chronic, inflammatory lung disease characterized by recurrent breathing problems. People with asthma have acute episodes where the air passages in their lungs get narrower, and breathing becomes more difficult. Sometimes episodes of asthma are triggered by allergens, although infection, exercise, cold air and other factors are also important triggers." rel="tooltip">Asthmacan be hard to predict. It can develop in youngchildrenand stay with them their entire lives. But some people don’t develop asthma until they areadults

In some people,asthma symptomsdon’t appear until they are exposed to a trigger such as smoke orpollen.他们的The immune system is a collection of cells and proteins that works to protect the body from potentially harmful, infectious microorganisms (microscopic life-forms), such as bacteria, viruses and fungi. The immune system plays a role in the control of cancer and other diseases, but also is the culprit in the phenomena of allergies, hypersensitivity and the rejection of transplanted organs, tissues and medical implants." rel="tooltip">immune systemviews these triggers as foreign substances and releases chemicals to combat them. For people with asthma, those chemicals can cause anasthma attack– meaning their airways tighten up, they have difficulty breathing and they may experiencecoughingor wheezing.

But if you haveasthma, don’t let the fear of an asthma attack hold you back! An allergist can identify your triggers, then create a plan to help you avoid and manage them.

If coughing and wheezing are keeping you on the sidelines…

It’s time for an allergist.

Common Triggers

Different allergens and irritants can act as triggers for different people, but common asthma triggers include:

  • Outdoor allergens, such aspollensfrom grass, trees and weeds
  • Indoor allergens, such aspet dander,dust mites, cockroaches andmold
  • Irritants in the air, such as smoke, chemical fumes and strong odors
  • Exercise(although people with well-controlled asthma can exercise)
  • Weather conditions, such as cold air or extremely dry, wet or windy weather
  • Certain drugs
  • Stress

Colds, Flu and Other Illnesses

Viral respiratory infections, including theflu, are the leading cause of acuteasthma attacks

有些人热衷ple with heartburn haveasthma symptomswhen stomach acid backs up into the esophagus.


Beta blockers, which often are prescribed for high blood pressure, glaucoma, migraine headaches and angina, can cause bronchospasm, an airway tightening. Patients with asthma should consult their allergist about the use of these medications.

Food additives rarely trigger asthma. The most common food trigger for asthma is sulfite, a preservative used in such products as frozen potatoes and some beers and wines.