Asthma

Source: MedlinePlus Health Topics, U.S. National Library of Medicine

What is asthma? Asthma is a chronic (long-term) lung disease. It affects your airways, the tubes that carry air in and out of your lungs. When you have asthma, your airways can become inflamed and narrowed. This can cause wheezing, coughing , and tightness in your chest. When these symptoms get worse than usual, it is called an asthma attack or flare-up. What causes asthma? The exact cause of asthma is unknown. Genetics and your environment likely play a role in who gets asthma. An asthma attack can happen when you are exposed to an asthma trigger. An asthma trigger is something that can set off or worsen your asthma symptoms. Different triggers can cause different types of asthma: Allergic asthma is caused by allergens. Allergens are substances that cause an allergic reaction. They can include Dust mites Mold Pets Pollen from grass, trees, and weeds Waste from pests such as cockroaches and mice Nonallergic asthma is caused by triggers that are not allergens, such as Breathing in cold air Certain medicines Household chemicals Infections such as colds and the flu Outdoor air pollution Tobacco smoke Occupational asthma is caused by breathing in chemicals or industrial dusts at work Exercise-induced asthma happens during physical exercise, especially when the air is dry Asthma triggers may be different for each person and can change over time. Who is at risk for asthma? Asthma affects people of all ages, but it often starts during childhood. Certain factors can raise your risk of having asthma: Being exposed to secondhand smoke when your mother is pregnant with you or when you are a small child Being exposed to certain substances at work , such as chemical irritants or industrial dusts Genetics and family history. You are more likely to have asthma if one of your parents has it, especially if it's your mother. Race or ethnicity. Black and African Americans and Puerto Ricans are at higher risk of asthma than people of other races or ethnicities. Having other diseases or