Asthma is a chronic condition in which the airways that carry air to the lungs are inflamed and narrowed.Inflamed airways are very sensitive, and they tend to react to things in the environment called triggers, such as substances that are inhaled. When the airways react, they swell and narrow even more, and also produce extra mucus, all of which make it harder for air to flow to the lungs. The muscles around the airways also tighten, which further restricts air flow.
When the airways react to asthma triggers, people can experience what’s called an asthma flare-up or asthma attack. Symptoms of an asthma attack include: coughing, chest tightness, wheezing and trouble breathing, according to the Centers for Disease Control and Prevention.
Some people have mild asthma symptoms, or only experience asthma symptoms in response to certain activities like exercising. Other people have more serve and frequent symptoms, which may need treatment with medication.
The underlying cause of asthma is not known, but it’s thought to be due to a combination of genetic and environmental factors. People with asthma may have genetic risk factors that make
them more susceptible to the disease, and certain environmental factors, such as exposure to allergens or certain viral infections in infancy, may increase the risk of developing the disease, according to the National Heart, Lung and Blood Institute (NHLBI).