What causes Asthma?

What Causes Asthma?

It is not clear exactly what makes the airways of people with asthma inflamed in the first place. Your inflamed airways may be due to a combination of things. We know that if other people in your family have asthma, you are more likely to develop it. New research suggests that being exposed to things like tobacco smoke, infections, and some allergens early in your life may increase your chances of developing asthma.
What Causes Asthma Symptoms and Attacks?
There are things in the environment that bring on your asthma symptoms and lead to asthma attacks. Some of the more common things include exercise, allergens, irritants, and viral infections. Some people have asthma only when they exercise or have a viral infection.
The list below gives some examples of things that can bring on asthma symptoms.

Allergens
Animal dander (from the skin, hair, or feathers of animals)
Dust mites (contained in house dust)
Cockroaches
Pollen from trees and grass
Mold (indoor and outdoor)
Irritants
Cigarette smoke
Air pollution
Cold air or changes in weather
Strong odors from painting or cooking
Scented products
Strong emotional expression (including crying or laughing hard) and stress
Others
Medicines such as aspirin and beta-blockers
Sulfites in food (dried fruit) or beverages (wine)
A condition called gastroesophageal (GAS-tro-e-sof-o-JEE-al) reflux disease that causes heartburn and can worsen asthma symptoms, especially at night
Irritants or allergens that you may be exposed to at your work, such as special chemicals or dusts
Infections
This is not a complete list of all the things that can bring on asthma symptoms. People can have trouble with one or more of these. It is important for you to learn which ones are problems for you. Your doctor can help you identify which things affect your asthma and ways to avoid them.
More Information under (NHLBI)