Asthma: Types, Triggers, Who Is at Risk, Symptoms, Diagnosis and Treatment

Asthma is a chronic (long-term) lung disease of the airways — the tubes that carry air in and out of the lungs. In asthma the airways can become inflamed and narrowed, causing wheezing, coughing and chest tightness. When symptoms get worse than usual, that is an asthma attack, or flare-up.

Causes and triggers

The exact cause of asthma is unknown; genetics and environment probably both play a part. An attack can happen on exposure to a trigger — something that sets off or worsens symptoms. Different triggers cause different types of asthma:

Triggers differ from person to person and can change over time.

Who is at risk

Asthma affects all ages but often starts in childhood. Risk is higher with:

• secondhand smoke exposure before birth (while the mother is pregnant) or as a small child;
• chemical irritants or industrial dusts at work;
• family history — especially a parent with asthma, and above all the mother;
• race or ethnicity — Black and African American and Puerto Rican people are at higher risk than other groups;
• other conditions such as obesity and allergies;
• frequent viral respiratory infections in early childhood;
• sex — among children asthma is more common in boys; among teens and adults, in women.

Symptoms

• chest tightness;
• coughing, especially at night or early in the morning;
• shortness of breath;
• wheezing — a whistling sound when breathing out.

Symptoms range from mild to severe, and may come every day or only now and then. In an attack they get much worse, gradually or suddenly. Attacks can be life-threatening, and are more common in severe asthma; frequent attacks may mean treatment needs to change.

Diagnosis

A health care provider may use:

• a physical exam and medical history;
• lung function tests, including spirometry, to see how well the lungs work;
• tests of how the airways react to specific exposures: you breathe in different concentrations of allergens or medicines that may tighten the airway muscles, with spirometry before and after;
• peak expiratory flow (PEF) — how fast you can blow air out with full effort;
• fractional exhaled nitric oxide (FeNO) — the nitric oxide in your breath; high levels may mean inflamed lungs;
• allergy skin or blood tests, if you have a history of allergies, to find which allergens trigger your immune system.

Treatment

You and your provider make a treatment plan to manage symptoms and prevent attacks. It includes:

• Avoiding triggers — if tobacco smoke is one, don't smoke, and don't let others smoke in your home or car.
• Quick-relief (short-term relief) medicines, to prevent or relieve symptoms during an attack — including an inhaler to carry at all times, and possibly other fast-acting medicines that open the airways.
• Control medicines, taken every day to prevent symptoms by reducing airway inflammation and preventing narrowing.

If a severe attack doesn't respond to quick-relief medicine, you need emergency care. Your provider may adjust treatment until symptoms are controlled.

Severe asthma. For some adults whose asthma other treatments cannot control, a provider may suggest bronchial thermoplasty: heat is used to shrink the smooth muscle in the lungs, which reduces the airways' ability to tighten and makes breathing easier. It has risks to discuss with your provider.

Sources

Based on "Asthma," MedlinePlus, National Library of Medicine; a work of the United States government in the public domain.