Asthma is a chronic disease of the airways that transport air to and from the lungs.In a person with asthma, the inside walls of the airways, known as bronchial tubes, become swollen or inflamed. This swelling or inflammation makes the airways extremely sensitive to irritations and increases their susceptibility to an allergic reaction.
In an allergic reaction, the airways swell, and the muscles around the airway tighten, making it difficult for air to move in and out of the lungs.
Asthma symptoms vary from person to person. You may have infrequent asthma attacks, have symptoms only at certain times — such as when exercising — or have symptoms all the time.
- Shortness of breath
- Chest tightness or pain
- Trouble sleeping caused by shortness of breath, coughing or wheezing
- A whistling or wheezing sound when exhaling (wheezing is a common sign of asthma in children)
- Coughing or wheezing attacks that are worsened by a respiratory virus, such as a cold or the flu
- Asthma signs and symptoms that are more frequent and bothersome
- Increasing difficulty breathing (measurable with a peak flow meter, a device used to check how well your lungs are working)
- The need to use a quick-relief inhaler more often
- Exercise-induced asthma, which may be worse when the air is cold and dry
- Occupational asthma, triggered by workplace irritants such as chemical fumes, gases or dust
- Allergy-induced asthma, triggered by airborne substances, such as pollen, mold spores, cockroach waste or particles of skin and dried saliva shed by pets (pet dander)
It isn't clear why some people get asthma and others don't, but it's probably due to a combination of environmental and genetic (inherited) factors.
Exposure to various irritants and substances that trigger allergies (allergens) can trigger signs and symptoms of asthma.
- Airborne substances, such as pollen, dust mites, mold spores, pet dander or particles of cockroach waste
- Respiratory infections, such as the common cold
- Physical activity (exercise-induced asthma)
- Cold air
- Air pollutants and irritants, such as smoke
- Certain medications, including beta blockers, aspirin, ibuprofen (Advil, Motrin IB, others) and naproxen (Aleve)
- Strong emotions and stress
- Sulfites and preservatives added to some types of foods and beverages, including shrimp, dried fruit, processed potatoes, beer and wine
- Gastroesophageal reflux disease (GERD), a condition in which stomach acids back up into your throat
- Having a blood relative (such as a parent or sibling) with asthma
- Having another allergic condition, such as atopic dermatitis or allergic rhinitis (hay fever)
- Being overweight
- Being a smoker
- Exposure to secondhand smoke
- Exposure to exhaust fumes or other types of pollution
- Exposure to occupational triggers, such as chemicals used in farming, hairdressing and manufacturing
The most common type of asthma is bronchial asthma, which affects the bronchi in the lungs.
Additional forms of asthma include childhood asthma and adult-onset asthma. In adult-onset asthma, symptoms don’t appear until at least age 20.
Other types of asthma are described below.
- Pet dander from animals like cats and dogs
- Food
- Mold
- Pollen
- Dust
Allergic asthma is more likely to be seasonal because it often goes hand-in-hand with seasonal allergies.
Irritants in the air not related to allergies trigger this type of asthma.
- Burning Wood and Cigarette Smoke
- Cold Air
- Air Pollution
- Viral illnesses
- Air Fresheners
- Household Cleaning Products
- Perfumes
- Dust
- Dyes
- Gases and Fumes
- Industrial Chemicals
- Animal Proteins
- Rubber Latex
These irritants can exist in a wide range of industries, including farming, textiles, woodworking, and manufacturing.