What is asthma?


Asthma: Overview

Asthma makes it hard for you to breathe. During an asthma attack, the airways swell and narrow. Severe asthma attacks can be dangerous, but you can usually prevent them. Controlling asthma and treating symptoms before they get bad can help you avoid bad attacks. You may also avoid future trips to the doctor.


Asthma is a long-term (chronic) disease of the respiratory system. It causes your airways to tighten and become narrow. This makes it hard to breathe and may cause wheezing and coughing.

Although asthma is a lifelong disease, treatment can help control it and help you stay healthy.

The cause of asthma is not clearly known.

What happens when you have asthma?

Asthma often starts when you're a child or teen, or you may get it as an adult. It usually lasts throughout your life.

At times, the inflammation from asthma causes your airways to narrow and mucus to increase. This causes asthma symptoms such as shortness of breath.

You may have symptoms every day or just now and then, or you may have something in between. Sometimes your symptoms may suddenly get worse (or flare up) and cause an asthma attack. Over time, your breathing problems may get more severe, or you may have symptoms more often.

You may have a hard time breathing only at certain times, like during allergy season, or when you get a cold, or when you exercise. Or you may have breathing problems a lot of the time. The things that make your asthma or breathing worse are called triggers.

Even mild asthma may cause long-term changes to your airways and lungs. It may speed up and make worse the natural decrease in lung function that occurs as we age. Asthma can make lung and airway infections like bronchitis and pneumonia worse.

Asthma may raise your risk for chronic obstructive pulmonary disease (COPD).

Asthma can occur for the first time during pregnancy, or it may change during pregnancy.

When asthma is well controlled, there are little or no increased risks to the pregnancy.

What are the symptoms of asthma?

When you have asthma, you may wheeze or cough a lot. You may also feel tightness in your chest or feel short of breath.

How is asthma treated?

Asthma is treated with medicine to help you breathe easier, along with self-care.

It's important to treat asthma, because even mild asthma can damage your airways. By following your treatment plan, you can meet your goals to:

  • Prevent symptoms.
  • Keep your lung function as close to normal as you can.
  • Be able to do your normal daily activities. This includes work, school, exercise, and recreation.
  • Prevent asthma attacks.
  • Have few or no side effects from medicine.


Most medicines for asthma are inhaled. These types of medicines go straight to your airways, where the problem is.

The main medicines used to treat asthma include:

Controller medicines.

These medicines prevent asthma attacks, stop problems before they happen, and reduce inflammation in your lungs. These things help you control your asthma.

If you have symptoms often, you will likely need to take your controller medicine daily. Inhaled corticosteroids are the preferred controller medicines. Your controller inhaler may also include a long-acting medicine that relaxes the airways to help you breathe.

Quick-relief medicines.

These medicines are used when you can't prevent symptoms and need to treat them fast.

These help relax the airways and allow you to breathe easier. Albuterol is a quick-relief medicine that is often used. In some cases, a certain type of controller inhaler is used as a quick-relief medicine. Ask your doctor what to use for quick relief.

Oral or injected corticosteroids.

These medicines may be used to treat asthma attacks.

Other medicines may be given in some cases.


There are things you can do to help manage your asthma. You can follow your asthma action plan and try to avoid things that trigger your symptoms.

Other treatments


If you have asthma symptoms that are triggered by allergens, your doctor may recommend immunotherapy. For this treatment, you get allergy shots that have a small amount of certain allergens in them. Your body "gets used to" the allergen, so you react less to it over time. This kind of treatment may help prevent or reduce some allergy symptoms.

For some people, allergy shots reduce asthma symptoms and the need for medicines. But allergy shots don't work equally well for all allergens. Allergy shots should not be given when asthma is not well-controlled.

How is asthma diagnosed?

To find out if you have asthma, your doctor will do a physical exam and ask you questions about your health.

Your doctor may also have you do breathing (lung function) tests to find out how well your lungs work. Your doctor may also do other tests to make sure your symptoms aren't caused by another lung or health problem.

Breathing (lung function) tests

Lung function tests can help your doctor diagnose asthma, see how bad it is, and check for problems. These tests may include:

  • Spirometry. Doctors use this test to diagnose and keep track of asthma. It measures how quickly you can move air in and out of your lungs and how much air you move.
  • Peak expiratory flow. This test shows how much air you can quickly breathe out as hard as you can. Testing of daytime changes in your peak flow may be done over 1 to 2 weeks. This test may help when you have symptoms off and on but your spirometry test results are normal.
  • An exercise or inhalation challenge. This test measures how well you can breathe in and out after exercise or after taking a medicine. It may be used if the spirometry test results have been normal or near normal but asthma is still suspected. This test also may be done using a specific irritant or allergen if your doctor thinks you may have occupational asthma.

Tests for other diseases

Asthma can be hard to diagnose because the symptoms vary widely. And asthma-like symptoms can also be caused by other conditions, such as a viral lung infection (like pneumonia), a vocal cord problem, or a problem with another organ, like your heart. So your doctor may want to do other tests.

  • More lung function tests may be needed if your doctor suspects another lung disease, such as chronic obstructive pulmonary disease (COPD).
  • An electrocardiogram (EKG or ECG) might be done to rule out serious conditions with similar symptoms, such as chronic heart failure. This test measures the electrical signals that control the rhythm of your heartbeat.
  • A bronchoscopy test can be done to examine the airways for problems such as tumors or foreign bodies. This test uses a long, thin, lighted tube to look at your airways.
  • A chest X-ray may be used to look for signs of other lung diseases, such as fibrous tissue caused by chronic inflammation (pulmonary fibrosis).
  • Blood tests, such as a complete blood count (CBC), may be done to look for signs of an infection or other condition.

If your doctor thinks your symptoms may be caused by allergies, your doctor may order allergy tests.

How is medicine used to treat asthma?

Medicine helps you breathe easier and control your asthma. It doesn't cure asthma. But it's an important part of managing it. Medicines for asthma treatment are used to:

  • Prevent and control airway inflammation. This is so you have fewer asthma symptoms.
  • Reduce how many asthma attacks you have, how long they last, and how bad they get.
  • Treat the attacks as they occur.

Medicine choices

Most medicines for asthma are inhaled. They allow a specific dose to be given directly to the airways.

The main medicines used to treat asthma include:

Controller medicines.
These medicines prevent asthma attacks, stop problems before they happen, and reduce inflammation in your lungs. These things help you control your asthma.

If you have symptoms often, you will likely need to take your controller medicine daily. Inhaled corticosteroids are the preferred controller medicines. They include budesonide, fluticasone and mometasone. Your controller medicine may also include a long-acting medicine that relaxes the airways to help you breathe.

Quick-relief medicines.

These medicines are used when you can't prevent symptoms and need to treat them fast.

Quick-relief medicines, such as beta2-agonists, help relax the airways and allow you to breathe easier. Albuterol is a quick-relief medicine that is often used. In some cases, a certain type of controller inhaler is used as a quick-relief medicine. Ask your doctor what to use for quick relief.

Oral or injected corticosteroids (systemic corticosteroids).

These medicines may be used to treat asthma attacks. The oral form is used much more than the injected form. They include methylprednisolone and prednisone.

There are other long-term medicines that are sometimes used alone or with other medicines. They include:

  • Anticholinergics (such as tiotropium). They treat asthma that's not well-controlled.
  • Leukotriene pathway modifiers. Examples are montelukast, zafirlukast, and zileuton.
  • Long-acting beta2-agonists. They are always used with an inhaled corticosteroid as a single medicine combination. They include formoterol and salmeterol.

Other medicines may be given in some cases.

  • Magnesium sulfate may be used if asthma doesn't improve with standard treatment.
  • Anticholinergics (such as ipratropium) are sometimes used for severe asthma attacks.
  • Your doctor may recommend other medicines if you have severe allergic asthma and the symptoms aren't relieved by avoiding allergens or by taking standard medicines. Examples include mepolizumab and omalizumab.

How your doctor prescribes asthma medicines

Medicine treatment for asthma depends on your age and type of asthma. It also depends on how well the treatment controls your asthma symptoms. Your doctor may use a different approach for your situation. The goal is to use the least amount of medicine you can to control asthma symptoms.

  • Your doctor may start you at a higher dose of medicine. Doing this can control the inflammation right away.
  • After the asthma has been controlled for several months, the dose of the last medicine added is reduced to the lowest possible dose that prevents symptoms. This is known as step-down care. It's thought to be a better way to control inflammation in the airways than starting at lower doses of medicine and raising the dose if it isn't enough.

You may also be started at the lowest dose that helps you.

  • The amount of medicine and number of medicines are increased in steps. So if asthma isn't controlled at a low dose of one controller medicine, the dose may be raised. Or another medicine may be added.
  • If the asthma has been under control for several months at a certain dose, the dose may be reduced. This can help find the least amount of medicine that will control the asthma.
  • Quick-relief medicine is used to treat asthma attacks. But if you need to use it a lot, the amount and number of controller medicines may be changed.

Do people who have asthma need to see a specialist?

Doctors who can diagnose and treat asthma include:

  • Pediatricians.
  • Family medicine physicians.
  • Nurse practitioners.
  • Physician assistants.
  • Internists.

You may need to see a specialist (allergist or pulmonologist) if you have:

  • Severe persistent asthma.
  • Other medical conditions that make it hard to treat asthma.
  • A need for more education or trouble following your asthma action plan.
  • Not met the goals of treatment after several months of therapy.
  • Had a life-threatening asthma attack.
  • Skin testing for allergies.
  • Occupational asthma.

How can you care for asthma in adults?

  • Follow your asthma action plan so you can manage your symptoms at home. An asthma action plan will help you prevent and control airway reactions and will tell you what to do during an asthma attack. If you do not have an asthma action plan, work with your doctor to build one.
  • Take your asthma medicine exactly as prescribed. Medicine plays an important role in controlling asthma. Talk to your doctor right away if you have any questions about what to take and how to take it.
    • Use your quick-relief medicine when you have symptoms of an asthma attack. Some people need to use quick-relief medicine before they exercise to prevent asthma symptoms. Albuterol is a quick-relief medicine that is often used. In some cases, a certain type of controller inhaler is used as a quick-relief medicine. Ask your doctor what to use for quick relief.
    • Take your controller medicine. If you have symptoms often, you will likely need to take it every day. Controller medicine usually includes an inhaled corticosteroid. The goal is to prevent problems before they occur.
    • If your doctor prescribed corticosteroid pills to use during an attack, take them as directed. They may take hours to work, but they may shorten the attack and help you breathe better.
    • Keep your quick-relief medicine with you at all times.
  • Talk to your doctor before using other medicines. Some medicines, such as aspirin, can cause asthma attacks in some people.
  • Check yourself for asthma symptoms to know which step to follow in your action plan. Watch for things like being short of breath, having chest tightness, coughing, and wheezing. Also notice if symptoms wake you up at night or if you get tired quickly when you exercise.
  • If you have a peak flow meter, use it to check how well you are breathing. This can help you predict when an asthma attack is going to occur. Then you can take medicine to prevent the asthma attack or make it less severe.
  • See your doctor regularly. These visits will help you learn more about asthma and what you can do to control it. Your doctor will monitor your treatment to make sure the medicine is helping you.
  • Keep track of your asthma attacks and your treatment. After you have had an attack, write down what triggered it, what helped end it, and any concerns you have about your asthma action plan. Take your diary when you see your doctor. You can then review your asthma action plan and decide if it is working.
  • Do not smoke or allow others to smoke around you. Avoid smoky places. Smoking makes asthma worse. If you need help quitting, talk to your doctor about stop-smoking programs and medicines. These can increase your chances of quitting for good.
  • Learn what triggers an asthma attack for you, and avoid the triggers when you can. Common triggers include colds, smoke, air pollution, dust, pollen, mold, pets, cockroaches, stress, and cold air.
  • Avoid infections such as COVID-19, colds, and the flu. Wash your hands often. Talk to your doctor about getting a pneumococcal vaccine. If you have had one before, ask your doctor if you need a second dose. Get a flu vaccine every fall. Stay up to date on your COVID-19 vaccines.

Teenagers: Feeling Different Because of Asthma

Stories From People Controlling Their Asthma

What puts you at risk for asthma?

You may be more likely to have asthma if:

  • Someone in your family has allergies or asthma.
  • You have an allergy. Asthma is much more common in people who have allergies, though not everyone with allergies gets asthma. And not everyone with asthma has allergies.

Other things that may put you at risk for asthma include:

  • Cigarette smoking.
  • Pollution.
  • Workplace irritants or allergens such as wood dust, plastics, and chemicals.
  • Allergens such as dust mites, cockroaches, and pet dander.

These same things can make your symptoms worse if you have asthma.

How is complementary medicine used to treat asthma?

Complementary medicine is a term used for a wide range of health care practices that may be used along with standard medical treatment.

Some people have found that mind and body practices such as acupuncture, breathing exercises, and yoga have been helpful for their asthma. But there is not evidence to say if these practices help.

Talk with your doctor if you are using complementary health practices or would like to. Your doctor can help you manage your health better if he or she knows all the treatments you use.

How are asthma and GERD related?

GERD is found in many people who have asthma.

Gastroesophageal reflux disease (GERD) is the abnormal backflow, or reflux, of stomach juices into the esophagus, the tube that leads from the throat to the stomach.

Some experts debate whether or to what extent GERD makes asthma worse. Studies have shown conflicting results as to whether GERD triggers asthma.

Those experts who believe GERD does trigger asthma theorize that the abnormal backflow of stomach juices irritates nerves in the esophagus. This could make the smooth muscles of the bronchial tubes tighten, causing airway narrowing. Or food may back up into the throat and airway, causing direct irritation of the bronchial tubes.

People with asthma who have heartburn—after meals, when they bend over, or when they lie down—may need to be treated for GERD. If you have persistent nighttime asthma symptoms, especially coughing and wheezing, GERD could be making your asthma symptoms worse. Steps you can take that may reduce the symptoms of GERD include losing weight (if needed), eating a low-fat diet, raising the head of your bed, and not eating for at least 3 hours before you go to bed.

What are the recommended goals for asthma treatment?

The goals for asthma treatment fall into two main areas. They are controlling asthma symptoms and reducing the risk for future problems.

Controlling symptoms

Many people with asthma can get their symptoms under control by avoiding things that might cause an asthma attack and using medicines. Asthma treatment should help you achieve good control of symptoms during the day, at night, and after exercise. These symptoms include wheezing, coughing, shortness of breath, and chest tightness.

When symptoms are under control, many people with asthma can do all the things they enjoy. And having control of asthma symptoms reduces the risk of future asthma attacks. Your asthma is well controlled if you:

  • Have daytime asthma symptoms 2 days a week or less.
  • Don't wake up at night because of your asthma more than 2 times a month.
  • Use a quick-relief inhaler 2 days a week or less. This does not include using your inhaler before exercise to prevent symptoms.
  • Can exercise, work, and go to school at your normal activity level.
  • Have lungs that are working as well as they can.

Reducing future problems

Another goal for treatment is to reduce the risk of having future asthma attacks. Smoking, vaping, and not using your inhalers correctly increase your chance of getting asthma attacks even if you have few or no asthma symptoms. Talk to your doctor if you need help quitting smoking or vaping. They can also teach you how to use your inhalers correctly.

Other goals of treatment are to prevent your lungs from getting worse and to have no side effects—or the fewest possible side effects—from your medicines.

Talk with your doctor about any other wishes or needs you may have for treating your asthma. They can be part of your shared goals.

Controlling your asthma: When to call

Call 911 anytime you think you may need emergency care. For example, call if:

  • You are having severe trouble breathing.

Call your doctor now or seek immediate medical care if:

  • Your symptoms do not get better after you have followed your asthma action plan.
  • You cough up yellow, dark brown, or bloody mucus (sputum).

Watch closely for changes in your health, and be sure to contact your doctor if:

  • Your coughing and wheezing get worse.
  • You need to use your quick-relief medicine on more than 2 days a week within a month (unless it is just for exercise).
  • You need help figuring out what is triggering your asthma attacks.

Working with your asthma doctor

Here are some ways to partner with your doctor to keep your asthma under control.

  • Work with your doctor to make an asthma action plan.
    • You and your doctor will make an asthma action plan that outlines the two approaches to taking charge of your asthma:
      • Controlling asthma over the long term. Controller medicine helps reduce the swelling of your airways and prevent attacks.
      • Treating attacks when they occur. The action plan will outline the steps to take and medicine to use to treat asthma attacks.
    • Let your doctor know what you want regarding asthma care. For example, if you are not sure how to use your inhalers, tell your doctor.
    • If you make an asthma action plan for your child, give a copy to the child's school or caregivers and make sure they know how to use it.
  • Have regular checkups with your doctor.

    During checkups, your doctor will ask if your symptoms or your peak flow, or both, have held steady, improved, or gotten worse. You will also be asked if you have asthma symptoms during exercise or at night. This information can help your doctor know if the severity of your asthma symptoms has changed or if you need to change medicines or doses.

    When you go to the doctor:

    • Take both your asthma action plan and your asthma diary. Get answers to any questions you have about your asthma plan or your symptoms.
    • Let your doctor know if treatment is not controlling your asthma symptoms.
    • Take your peak flow meter (if you use one) and your medicines so your doctor can review your treatment and the way you use the meter and medicines.
    • Make sure you know how and when to call your doctor or go to the hospital.
    • Tell your doctor if you are not able to follow your action plan.

Self-assessment: How well do you understand asthma?

Understanding asthma can help you control your symptoms and reduce your risk of asthma attacks.

The following statements summarize what you should know about asthma. If you don't know or aren't sure about any of them, talk to your doctor. The more you understand about asthma, the better you will be able to follow your management plan and lead a full life.

Asthma self-assessment


Yes, I do

No, I don't

I'm not sure

I know what asthma is and what it does to me.

I know the symptoms of asthma.

I know how my asthma medicines help me.

I know what my asthma triggers are and what to do about them.

I feel sure that I can prevent an asthma attack.

I know how to treat my asthma symptoms.

I know when my symptoms are serious enough to call for emergency help.

I know how to use my asthma action plan.

I do what I enjoy doing, despite my asthma.

I know that people around me can help me if needed.

Asthma: What Happens in Your Lungs

How can you help your teen manage their asthma care?

Teens who have asthma may see the illness as cutting into their freedom. They may feel that it sets them apart from their friends.

But there are ways you can help your teen manage their asthma care.

  • Help your teen remember that asthma is only one part of life.
  • Let your teen meet with the doctor alone.
  • Work out a daily asthma plan that lets your teen keep doing daily activities like sports.
  • Help your teen understand that asthma doesn't have to hold them back and that taking the asthma medicine will help your teen lead an active life.
  • Talk with your teen about the dangers of smoking and drug use.
  • Help your teen meet others who have asthma so they can support each other.

Finding your asthma triggers

If you avoid triggers, you can prevent some asthma attacks. Here are some ways to learn what your asthma triggers are.

  • Identify possible asthma triggers.

    When you're around something that triggers your symptoms, keep track of it. This can help you find a pattern in what triggers your symptoms. Record triggers in your asthma diary or on your asthma action plan.

  • Monitor your lung function.

    Watch for things like being short of breath, having chest tightness, coughing, and wheezing. Also notice if symptoms wake you up at night or if you get tired quickly when you exercise.

    If your doctor recommends it, measure your peak expiratory flow (PEF), or "peak flow." A trigger may not always cause symptoms. But it can still narrow your bronchial tubes, which makes your lungs work harder. To identify triggers that don't always cause symptoms right away, you can measure your peak flow throughout the day. Your peak flow will drop when your bronchial tubes narrow, so it will drop when you're near things that cause your airways to narrow.

  • Be tested for allergies.

    Skin or blood testing may be used to diagnose allergies to certain substances. Skin testing involves pricking the skin on your back or arms with one or more small doses of specific allergens. The amount of swelling and redness at the sites where your skin was pricked is measured to find allergens you react to.

  • Share your trigger record with your doctor.

    After you have found some things that may trigger your asthma, you and your doctor can make a plan for how to deal with them.

How does asthma affect your breathing?

With asthma, you may have trouble breathing. Your symptoms may be mild, moderate, or severe. For example, you may notice that your breathing goes from being slightly faster than normal to very fast. Or you may tire when you talk or eat or may be unable to eat because it's too hard to breathe.

How can you get past barriers to managing your asthma?

At times, you may find it hard to manage your asthma and stay with your treatment plan. If you're having trouble, it may help to figure out what's getting in your way. Then you can decide how to work around those barriers.

Here are some common barriers people face when following a plan and some ideas for dealing with the barriers.

  • "Maybe my asthma isn't all that serious. My symptoms are so mild that I don't feel I need treatment."
    • Learn all you can about asthma. Even if you have no symptoms, asthma can hurt your lungs. It can lead to worse symptoms later in life.
    • Understand both the benefits of treating asthma and the risks of not treating asthma.
  • "It's hard to talk about my plan with my doctor or pharmacist because they're so far away."
    • Work with others to ensure that you have transportation to your doctor and pharmacy. Or ask about setting up an online appointment with your doctor.
  • "It's hard for me to talk with my doctor or pharmacist because of language barriers."
    • If language is a problem, ask for translation services.
  • "I don't understand my plan or my medicines."
    • Work with your doctor to develop personal goals and expectations for your treatment.
    • If you don't understand something, ask about it.
  • "I just don't trust them."
    • If you don't feel comfortable with your doctor or pharmacist, think about looking for a new one.

Asthma: Fast facts

What causes asthma?

Experts don't know exactly what causes asthma. But we do know that asthma runs in families. And it's much more common in people who have allergies.

What are peak flow and personal best for asthma?

Peak expiratory flow, or peak flow, is how much air you breathe out when you try your hardest. You measure peak flow with a peak flow meter, a device that you can use at home.

  • If you can breathe out quickly and with ease, you have a higher number. This means you have a higher peak flow. Your lungs are working well, and your asthma may not be bothering you.
  • If you can only breathe out slowly and with difficulty, you have a lower number. This means you have a lower peak flow. Your lungs aren't working well, even if you aren't having asthma symptoms.

A person's personal best is their highest peak flow reading. You can find your or your child's personal best by taking peak flow readings over 2 to 3 weeks when the asthma is under control—when you or your child feels good and has no symptoms. During these weeks, peak flows should be recorded at least 2 times a day. Your personal best is the highest reading you have over this period of time.

©2011-2024 Healthwise, Incorporated

The content above contains general health information provided by Healthwise, Incorporated, and reviewed by its medical experts. This content should not replace the advice of your healthcare provider. Not all treatments or services described are offered as services by us. For recommended treatments, please consult your healthcare provider.

Specialized emergency services

Find care near you

Comprehensive care

Find an ER near you