Asthma is a disease that causes the inside of airways to become inflamed, or swollen. This inflammation makes the airways sensitive and can cause strong reactions to allergens and other irritants.
Asthma is a chronic disease that affects your airways, the tubes that carry air in and out of your lungs. In asthma, the inside walls of your airways are inflamed, or swollen. The inflammation makes them very sensitive, and they tend to react strongly to things that you are allergic to or find irritating.
Put simply, asthma is primarily a chronic inflammatory disease of the airways. This means that people with asthma have inflamed airways, which causes two secondary symptoms. First, the bronchi, which are the airway branches leading to the lungs, become overly reactive and more sensitive to all kinds of asthma triggers, such as allergens, cold and dry air, smoke and viruses.
Second, the lungs have difficulty moving air in and out, which is called airflow obstruction. Together, these symptoms cause the additional symptoms of coughing, wheezing, chest tightness and others. These symptoms are most common at night and in the early morning.
When your asthma symptoms become worse than usual, it's called an asthma episode or attack. In a severe asthma attack, the airways can close so much that not enough oxygen can get to your vital organs. In some cases, asthma attacks can be fatal.
Unfortunately, asthma can't be cured. However, most people with asthma can control it so that they have fewer, less-frequent symptoms and can live normal, active lives.