What Is Asthma?

Asthma is a chronic disease that affects your airways. The airways are the tubes that carry air in and out of your lungs. If you have asthma, the inside walls of your airways are inflamed (swollen). The inflammation makes the airways very sensitive, and they tend to react strongly to things that you are allergic to or find irritating. When the airways react, they get narrower, and less air flows through to your lung tissue. This causes symptoms like wheezing (a whistling sound when you breathe), coughing, chest tightness, and trouble breathing, especially at night and in the early morning.

Who Is At Risk for Asthma?

In the United States, about 20 million people have been diagnosed with asthma; nearly 9 million of them are children.

Asthma is closely linked to allergies. Most, but not all, people with asthma have allergies. Children with a family history of allergy and asthma are more likely to have asthma.

Although asthma affects people of all ages, it most often starts in childhood. More boys have asthma than girls, but in adulthood, more women have asthma than men.

Although asthma affects people of all races, African Americans are more likely than Caucasians to be hospitalized for asthma attacks and to die from asthma.

Can Asthma Be Cured?

Asthma cannot be cured, but most people with asthma can control it so that they have few and infrequent symptoms and can live active lives.

When your asthma symptoms become worse than usual, it is called an asthma episode or attack. During an asthma attack, muscles around the airways tighten up, making the airways narrower so less air flows through. Inflammation increases, and the airways become more swollen and even narrower. Cells in the airways may also make more mucus than usual. This extra mucus also narrows the airways. These changes make it harder to breathe.

What Are the Signs and Symptoms of Asthma?

Common asthma symptoms include:

* Coughing. Coughing from asthma is often worse at night or early in the morning, making it hard to sleep.

* Wheezing. Wheezing is a whistling or squeaky sound when you breathe.

* Chest tightness. This can feel like something is squeezing or sitting on your chest.

* Shortness of breath. Some people say they can't catch their breath, or they feel breathless or out of breath. You may feel like you can't get enough air in or out of your lungs.

* Faster breathing or noisy breathing.

Not all people have these symptoms, and symptoms may vary from one asthma attack to another. Symptoms can differ in how severe they are: Sometimes symptoms can be mildly annoying, other times they can be serious enough to make you stop what you are doing, and sometimes symptoms can be so serious that they are life threatening.

Symptoms also differ in how often they occur. Some people with asthma have symptoms only once every few months, others have symptoms every week, and still other people have symptoms every day. With proper treatment, however, most people with asthma can expect to have few or no symptoms.

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

Key Points

* 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. When they react, they get narrower and less air flows through to your lungs. This causes symptoms like wheezing, coughing, chest tightness, and trouble breathing, especially at night and in the early morning.

* Asthma cannot be cured, but most people with asthma can control it so that they have few and infrequent symptoms and can live normal, active lives.

* When your asthma symptoms become worse than usual, it is 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. People can die from severe asthma attacks.

* Taking care of your asthma is an important part of your life. Controlling it means working closely with your doctor to learn how to manage your condition, staying away from things that bother your airways and bring on asthma symptoms, taking medicines as directed by your doctor, and monitoring your asthma so you can respond quickly to signs of an attack. Ask your doctor for a written daily asthma self-management plan and an emergency action plan for asthma attacks, and make sure you understand and know how to use them.

* Researchers still do not know what causes asthma, although they do know that if other people in your family have asthma, you are more likely to develop it. Being exposed early in your life to things like tobacco smoke, infections, and some allergens may also increase your chances of developing asthma.

* Some of the more common things that bring on asthma symptoms include exercise, allergens, irritants, and viral infections.

* Common asthma symptoms include coughing, wheezing, chest tightness, shortness of breath, and faster or noisy breathing.

* Doctors find out whether you have asthma by looking at your family history of asthma and allergies, exploring the things that seem to cause your symptoms or make them worse, and giving you a test, called spirometry, that measures how much air you can blow out of your lungs after taking a deep breath and how quickly you can do it. They may also perform tests to find out if you have allergies, to see how your airways react to exercise, to find out whether you have gastroesophageal reflux disease or sinus disease, and to rule out heart disease and other lung diseases.

* Asthma is treated with two kinds of medicines: quick-relief medicines to stop asthma symptoms and long-term control medicines to prevent symptoms.

* Short-acting inhaled beta-agonists are the preferred quick-relief medicine. The most effective, long-term control medicine is an inhaled corticosteroid, which reduces inflammation in your lungs. Most long-term control medicines must be taken daily, even when you do not have symptoms.

* Other long-term control medicines include inhaled long-acting beta-agonists, leukotriene modifiers, cromolyn, and theophylline.

* Most asthma medicines are inhaled. As a result, they go straight to your lungs where they are needed. It is important to learn how to use your inhalers correctly.

* Many people with asthma need to monitor their condition with a peak flow meter. This is a hand-held device that measures how well your lungs are working. A peak flow meter can help you detect early changes in your condition, especially if you change your medicines, and warn you of a possible attack even before you feel symptoms.

* Parents of children with asthma need to help them manage their asthma, including making sure the child uses his or her medicines properly and watching for any signs of an attack.

* Older people with asthma may need to adjust their treatment because of other diseases or conditions that they have. Some medicines that many older people take can interfere with asthma medicines or even cause asthma attacks.

* It is especially important for pregnant women with asthma to control their asthma. Uncontrolled asthma can limit the supply of oxygen to the fetus. Doctors recommend that it is safer to take asthma medicines during pregnancy than to take the chance that you will have an attack.

* Regular physical activity is just as important for people with asthma as for the rest of the population. If exercise brings on your asthma symptoms, talk to your doctor about the best ways to control your asthma when you are active.

Source: National Institutes of Health

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