Asthma is a chronic disease that causes the airways of the lungs to swell and narrow. It leads to breathing difficulty such as wheezing, shortness of breath, chest tightness, and coughing.
Bronchial asthma; Wheezing - asthma - adults
Asthma is caused by swelling (inflammation) in the airways. When an asthma attack occurs, the lining of the air passages swells and the muscles surrounding the airways become tight. This reduces the amount of air that can pass through the airway.
Asthma symptoms can be caused by breathing in substances called allergens or triggers, or by other causes.
Common asthma triggers include:
- Animals (pet hair or dander)
- Dust mites
- Certain medicines (aspirin and other NSAIDS)
- Changes in weather (most often cold weather)
- Chemicals in the air or in food
- Physical activity
- Respiratory infections, such as the common cold
- Strong emotions (stress)
- Tobacco smoke
Substances in some workplaces can also trigger asthma symptoms, leading to occupational asthma. The most common triggers are wood dust, grain dust, animal dander, fungi, or chemicals.