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What is asthma?

Asthma (Az-muh) 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.

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 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.

asthma graphic showing normal and asthmatic airwaysAsthma attacks are not all the same—some are worse than others. In a severe asthma attack, the airways can close so much that not enough oxygen gets to vital organs. This condition is a medical emergency. People can die from severe asthma attacks.

So, if you have asthma, you should see your doctor regularly. You will need to learn what things cause your asthma symptoms and how to avoid them. Your health care provider will also prescribe medicines to keep your asthma under control.

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.


  • 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)


  • 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


  • 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

This is not a complete list of all the things that can bring on asthma symptoms. People can have trouble with one or more of these. It is important for you to learn which ones are problems for you. Your medical provider can help you identify which things affect your asthma and ways to avoid them.

What are the signs and symptoms of asthma?

Common asthma symptoms include:

  • Coughing from asthma is often worse at night or early in the morning, making it hard to sleep.
  • Wheezing is a whistling or squeaky sound when you breathe.
  • Chest tightness, which can feel like something is squeezing or sitting on your chest.
  • 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 and how often they are: Sometimes symptoms can be mildly annoying, other times they can be serious and persistent enough to make you stop what you are doing, and sometimes symptoms can be so serious and frequent that they are life threatening.

How is asthma diagnosed?

Some things your provider will ask about include:

  • Periods of coughing, wheezing, shortness of breath, or chest tightness that come on suddenly, occur often, or seem to happen during certain times of the year or season
  • Colds that seem to "go to the chest" or take more than 10 days to get over
  • Medicines you may have used to help your breathing
  • Your family history of asthma and allergies
  • Things that seem to cause your symptoms or make them worse

Your health care provider will listen to your breathing and look for signs of asthma or allergies.

Your medical provider will probably use a device called a spirometer to check how your lungs are working. This test is called spirometry. The test measures how much air you can blow out of your lungs after taking a deep breath, and how fast you can do it . The results will be lower than normal if your airways are inflamed and narrowed, or if the muscles around your airways have tightened up.

As part of the test, your health care provider may give you a medicine that helps open narrowed airways to see if the medicine changes or improves your test results.

  • Spirometry is also used to check your asthma over time to see how you are doing.
  • Spirometry usually cannot be used in children younger than 5 years. If your child is younger than 5 years, the medical provider may decide to try medicine for a while to see if the child's symptoms get better.
  • If your spirometry results are normal but you have asthma symptoms, your provider will probably want you to have other tests to see what else could be causing your symptoms. These include
    • Allergy testing to find out if and what allergens affect you.
    • A test in which you use a peak flow meter every day for 1-2 weeks to check your breathing. A peak flow meter is a hand-held device that helps you monitor how well you are breathing.
    • A test to see how your airways react to exercise.
    • Tests to see if you have gastroesophageal reflux disease.
    • A test to see if you have sinus disease.

Other tests, such as a chest x ray or an electrocardiogram, may be needed to find out if a foreign object or other lung diseases or heart disease could be causing your symptoms. A correct diagnosis is important because asthma is treated differently from other diseases with similar symptoms.

Depending on the results of your physical exam, medical history, and lung function tests, your provider can determine how severe your asthma is. This is important because the severity of your asthma will determine how your asthma should be treated. One way for medical practitioners to classify asthma severity is by considering how often you have symptoms when you are not taking any medicine or when your asthma is not well controlled.

Based on symptoms, the four levels of asthma severity are:

  • Mild intermittent (comes and goes)—you have episodes of asthma symptoms twice a week or less, and you are bothered by symptoms at night twice a month or less; between episodes, however, you have no symptoms and your lung function is normal.
  • Mild persistent asthma—you have asthma symptoms more than twice a week, but no more than once in a single day. You are bothered by symptoms at night more than twice a month. You may have asthma attacks that affect your activity.
  • Moderate persistent asthma—you have asthma symptoms every day, and you are bothered by nighttime symptoms more than once a week. Asthma attacks may affect your activity.
  • Severe persistent asthma—you have symptoms throughout the day on most days, and you are bothered by nighttime symptoms often. In severe asthma, your physical activity is likely to be limited.

Anyone with asthma can have a severe attack—even people who have intermittent or mild persistent asthma.

How is asthma treated?

Your health care provider can work with you to decide about your treatment goals and what you need to do to control your asthma to achieve these goals. Asthma treatment includes:

  • Working closely with your doctor to decide what your treatment goals are and learning how to meet those goals.
  • Avoiding things that bring on your asthma symptoms or make your symptoms worse. Doing so can reduce the amount of medicine you need to control your asthma.
  • Using asthma medicines. Allergy medicine and shots may also help control asthma in some people.
  • Monitoring your asthma so that you can recognize when your symptoms are getting worse and respond quickly to prevent or stop an asthma attack.

With proper treatment, you should ideally have these results:

  • Your asthma should be controlled.
  • You should be free of asthma symptoms.
  • You should have fewer attacks.
  • You should need to use quick-relief medicines less often.
  • You should be able to do normal activities without having symptoms.

Your medical provider will work with you to develop an asthma self-management plan for controlling your asthma on a daily basis and an emergency action plan for stopping asthma attacks. These plans will tell you what medicines you should take and other things you should do to keep your asthma under control.

Medicines for asthma

There are two main types of medicines for asthma:

  • Quick-relief medicines—taken at the first signs of asthma symptoms for immediate relief of these symptoms. You will feel the effects of these medicines within minutes.
  • Long-term control medicines—taken every day, usually over long periods of time, to prevent symptoms and asthma episodes or attacks. You will feel the full effects of these medicines after taking them for a few weeks. People with persistent asthma need long-term control medicines.

Quick-relief medicines

Everyone with asthma needs a quick-relief or "rescue" medicine to stop asthma symptoms before they get worse. Short-acting inhaled beta-agonists are the preferred quick-relief medicine. These medicines are bronchodilators. They act quickly to relax tightened muscles around your airways so that the airways can open up and allow more air to flow through.

You should take your quick-relief medicine when you first begin to feel asthma symptoms, such as coughing, wheezing, chest tightness, or shortness of breath. You should carry your quick-relief inhaler with you at all times in case of an asthma attack.

Your medical provider may recommend that you take your quick-relief medicines at other times as well—for example, before exercise.

Long-term control medicines

The most effective, long-term control medicine for asthma is an inhaled corticosteroid (kor-ti-ko-STE-roid) because this medicine reduces the airway swelling that makes asthma attacks more likely.

Inhaled corticosteroids (or steroids for short) are the preferred medicine for controlling mild, moderate, and severe persistent asthma. They are generally safe when taken as directed by your health care provider.

In some cases, steroid tablets or liquid are used for short periods of time to bring asthma under control. The tablet or liquid form may also be used to control severe asthma.

Other long-term control medicines include:

  • Inhaled long-acting beta-agonists. These medicines are bronchodilators, or muscle relaxers, not anti-inflammatory drugs. They are used to help control moderate and severe asthma and to prevent nighttime symptoms. Long-acting beta-agonists are usually taken together with inhaled corticosteroid medicines.
  • Leukotriene modifiers (montelukast, zafirlukast, and zileuton), which are used either alone to treat mild persistent asthma or together with inhaled corticosteroids to treat moderate or severe asthma.
  • Cromolyn and nedocromil, which are used to treat mild persistent asthma.
  • Theophylline, which is used either alone to treat mild persistent asthma or together with inhaled corticosteroids to treat moderate persistent asthma. People who take theophylline should have their blood levels checked to be sure the dose is appropriate.

If you stop taking long-term control medicines, your asthma will likely worsen again.

Many people with asthma need both a short-acting bronchodilator to use when symptoms worsen and long-term daily asthma control medicines to treat the ongoing inflammation.

Over time, your medical provider may need to make changes in your asthma medicine. You may need to increase your dose, lower your dose, or try a combination of medicines. Be sure to work with your provider to find the best treatment for your asthma. The goal is to use the least amount of medicine necessary to control your asthma.

Most asthma medicines are inhaled. They go directly into your lungs where they are needed. There are many kinds of inhalers, and many require different techniques. It is important to know how to use your inhaler correctly.

Use a Peak Flow Meter

As part of your daily asthma self-management plan, your health care practitioner may recommend that you use a hand-held device called a peak flow meter at home to monitor how well your lungs are working.

You use the peak flow meter by taking a deep breath in and then blowing the air out hard into the peak flow meter. The peak flow meter then gives you a peak flow number that tells you how fast you moved the air out.

You will need to find out your "personal best" peak flow number. You do this by recording your peak flow number every day for a few weeks until your asthma is under control. The highest number you get during that time is your personal best peak flow. Then you can compare future peak flow measurements to your personal best peak flow, and that will show if your asthma is staying under control.

Your provider will tell you how and when to use your peak flow meter and how to use your medicines based on the results. You may be advised to use your peak flow meter each morning to keep track of how well you are breathing.

Your peak flow meter can help warn you of a possible asthma attack even before you notice symptoms. If your peak flow meter shows that your breathing is getting worse, you should follow your emergency asthma action plan. Take your quick-relief or other medicines as your doctor directed. Then you can use the peak flow meter to see how your airways are responding to the medicine.

Ask your provider about how you can take care of your asthma. You should know:

  • What things tend to make your asthma worse and how to avoid them
  • Early signs to watch for that mean your asthma is starting to get worse (like a drop in your peak flow number or an increase in symptoms)
  • How and when to use your peak flow meter
  • What medicines to take, how much to take, when to take them, and how to take them correctly
  • When to call or see your health care provider
  • When you should get emergency treatment

Additional resources

On campus

Contact Hall Health to schedule an appointment.

UW Allergy, Asthma and Immunology Clinic

UW General Pulmonary Clinic


Major portions of this article were reprinted from the National Heart, Lung, and Blood Institute's asthma resources.


Authored by: Hall Health Center Primary Care Clinic staff, reprinted from the National Heart, Lung and Blood Institute

Reviewed by: Hall Health Center Primary Care Clinic staff (KC), February 2014