Main Causes of Asthma

ASTHMA IS IN YOUR LUNGS WHETHER YOU FEEL IT OR NOT

Asthma is a chronic disease of the airways of the lungs. Unfortunately, asthma never goes away, but the right treatment can help keep it under control.

CAUSES OF ASTHMA

Some people think there is only one cause of asthma symptoms. But actually, asthma symptoms have two main causes, and both occur within the airways of your lungs:

AIRWAY CONSTRICTION

This is the cause of asthma symptoms that you may feel as a tightening in your chest. The muscles around the airways of your lungs squeeze together or tighten. This tightening is often called "bronchoconstriction," and it can make it hard for you to breathe.

INFLAMMATION

This is the cause of asthma symptoms you probably do not notice. If you have asthma, the airways of your lungs are always inflamed, and they become more swollen and irritated when your asthma symptoms worsen. Inflammation can reduce the amount of air that you can take in or breathe out. In some cases, too much thick mucus is produced, which further obstructs the airways.

Together, airway constriction and inflammation narrow your airways, which can result in wheezing, coughing, chest tightness, or shortness of breath—likely familiar feelings to you. And in people with asthma, the airways may be inflamed even when they are not having symptoms.

Source - http://www.asthma.com