When asthma symptoms appear and are diagnosed in adults older than 20, it is typically known as adult-onset asthma. Adult-onset asthma is more common in women than in men and is possibly related to allergies or allergic asthma. About half of adults who have asthma also have allergies. At other times, adult-onset asthma may be the result of commonplace substances in work (called occupational asthma) or home environments, and the asthma symptoms come on suddenly.

What is asthma?

Asthma is a disorder of the lungs that causes the airways to:

  • Swell (or become inflamed), specifically in the airway linings

  • Produce large amounts of mucus that is thicker than normal

  • Become more narrow because of muscle contractions surrounding the airways

The symptoms of asthma include:

  • Feeling short of breath

  • Frequent coughing, especially at night

  • Wheezing (a whistling noise during breathing)

  • Difficulty breathing

What is adult-onset asthma?

When a doctor makes a diagnosis of asthma in people older than 20, it is known as adult-onset asthma.

Among those who may be more likely to get adult-onset asthma are:

  • Women who are having hormonal changes, such as those who are pregnant or who are experiencing menopause

  • Women who take estrogen following menopause for 10 years or longer

  • People who have just had certain viruses or illnesses, such as a cold or flu

  • Obese people

  • People with allergies, especially to cats

  • People who are exposed to environmental irritants, such as tobacco smoke, mold, dust, feather beds, or perfume. Irritants that bring on asthma symptoms are called "asthma triggers." Asthma brought on by workplace triggers is called "occupational asthma."

Quick GuideAsthma Symptoms, Causes, and Medications

Asthma Symptoms, Causes, and Medications

What is the difference between childhood asthma and adult-onset asthma?

Symptoms of asthma in children may come and go, while symptoms of adult-onset asthma may be continuous. People with adult-onset asthma may need to take medication every day to manage asthma.

Adults tend to have lower lung capacity (the volume of air you are able to take in and forcibly exhale in one second) after middle age because of changes in muscles and stiffening of chest walls. This decreased capacity may cause doctors to miss the diagnosis of adult-onset asthma.

How is adult-onset asthma diagnosed?

Your asthma doctor may diagnose adult-onset asthma by:

  • Taking a medical history, asking about symptoms, and listening to you breathe

  • Performing a lung function test, using a device called a spirometer to measure how much air you can exhale after first taking a deep breath. The device also measures how fast you can empty your lungs. You may be asked at some time before or after the test to inhale a short-acting bronchodilator (medicine that opens the airways by relaxing tight muscles and that also help clear mucus from the lungs).

  • Performing a methacholine challenge test. This asthma test may be performed if your symptoms and spirometry test do not clearly show asthma. When inhaled, methacholine causes the airways to spasm and narrow if asthma is present. During this test, you inhale increasing amounts of methacholine aerosol mist before and after spirometry. The methacholine test is considered positive, meaning asthma is present, if the lung function drops by at least 20%. A bronchodilator is always given at the end of the test to reverse the effects of the methacholine.

  • Performing a chest X-ray. An X-ray is an image of the body that is created by using low doses of radiation reflected on special film or a fluorescent screen. X-rays can be used to diagnose a wide range of conditions, from bronchitis to a broken bone. Your doctor might perform an X-ray exam on you in order to see the structures inside your chest, including the heart, lungs, and bones. By viewing your lungs, your doctor can see if you have a condition other than asthma that may account for your symptoms. Although there may be signs on an X-ray that suggest asthma, a person with asthma will often have a normal chest X-ray.

Who gets asthma?

Anyone can get asthma at any age. Among those at higher risk for asthma are people who:

  • Have a family history of asthma

  • Have a history of allergies (allergic asthma)

  • Have smokers living in the household

  • Live in urban areas

How is asthma classified?

Asthma is classified into four categories based upon frequency of symptoms and objective measures, such as peak flow measurements and/or spirometry results. These categories are: mild intermittent; mild persistent; moderate persistent; and severe persistent. Your physician will determine the severity and control of your asthma based on how frequently you have symptoms and on lung function tests. It is important to note that a person's asthma symptoms can change from one category to another.

Mild intermittent asthma

  • Symptoms occur less than two times a week, and nighttime symptoms occur less than two times per month.

  • Asthma episodes are brief (a few hours to a few days).

  • Lung function tests are greater than 80% of predicted values. Predictions are often made on the basis of age, sex, and height. For a person with asthma, the "predicted" figure could be replaced by the person's own personal best test value as the figure for comparison.

Mild persistent asthma

  • Symptoms occur more than two times per week but not every day.

  • Lung function tests are greater than 80% of predicted.

Moderate persistent asthma

  • Symptoms occur daily.

  • Asthma symptoms affect activity, occur more than two times per week, and may last for days.

  • There is a reduction in lung function, with a lung function test range of 60% to 80% of predicted.

Severe persistent asthma

  • Symptoms occur continuously, with asthma at night frequently.

  • Activities are limited.

  • Lung function is decreased to less than 60% of predicted.

How is asthma treated?

Asthma can be controlled, but there's no asthma cure. There are certain goals in asthma treatment. If you are unable to achieve all of these goals, it means asthma is not in good control. You should contact your asthma care provider for help with asthma.

The treatment goals include the following:

  • Live an active, normal life.

  • Prevent chronic and troublesome symptoms.

  • Attend work or school every day.

  • Perform daily activities without difficulty.

  • Stop urgent visits to the doctor, emergency room, or hospital.

  • Use and adjust medications to control asthma with little or no side effects.

Properly using asthma medication, as prescribed by your doctor, is the basis of good asthma control, in addition to avoiding triggers and monitoring daily asthma symptoms. There are two main types of asthma medications:

  • Anti-inflammatories: This is the most important type of medication for most people with asthma. Anti-inflammatory medications, such as inhaled steroids, reduce swelling and mucus production in the airways. As a result, airways are less sensitive and less likely to react to triggers. These medications need to be taken daily, and may need to be taken for several weeks before they begin to control asthma. Anti-inflammatories lead to a reduction in symptoms, better airflow, less sensitive airways, less airway damage, and fewer asthma episodes. If taken every day, they are helpful in controlling or preventing asthma.

  • Bronchodilators: These medications relax the muscle bands that tighten around the airways. This action rapidly opens the airways, letting more air in and out of the lungs and improving breathing. Bronchodilators also help clear mucus from the lungs. As the airways open, the mucus moves more freely and can be coughed out more easily. In short-acting forms, bronchodilators relieve or stop asthma symptoms and are very helpful during an asthma episode. In long-acting forms, bronchodilators provide control of asthma symptoms and prevent asthma episodes.

Asthma medications can be taken by inhaling the medications (using a metered dose inhaler, dry powder inhaler, or asthma nebulizer) or by swallowing oral medications (pills or liquids). If you are also taking drugs for other conditions, you should work with your providers to check drug interactions and simplify medications when possible.

Monitoring symptoms

An important part of treatment is keeping track of how well the lungs are functioning. Asthma symptoms are monitored using a peak flow meter. The meter can alert you to changes in the airways that may be a sign of worsening asthma. By taking daily peak flow readings, you can learn when to adjust medications to keep asthma under good control. Your doctor can also use this information to adjust your treatment plan.

Asthma action plan

Based on your history and the severity of asthma, your doctor will develop a care plan called an asthma action plan. The asthma action plan describes when and how to use asthma medications, actions to take when asthma worsens, and when to seek care for an asthma emergency. Make sure you understand this plan; if not, ask your asthma care provider any questions you may have.

WebMD Medical Reference

Reviewed by Jonathan L. Gelfand, MD, on August 1, 2007

© 2007 WebMD, Inc. All rights reserved.

Quick GuideAsthma Symptoms, Causes, and Medications

Asthma Symptoms, Causes, and Medications

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