An Overview of Asthma

Medically Reviewed By Adithya Cattamanchi, M.D.

Asthma is a chronic lung disease marked by acute flare-ups of inflammation and swelling of the airways. These flare-ups, also called asthma attacks, can cause breathing difficulties, wheezing, and coughing. Many people need medications like inhaled corticosteroids or bronchodilators to manage their symptoms. Also, limiting exposure to triggers — such as pollen, cold air, or respiratory infections — can help prevent asthma attacks.

Read on to learn more about asthma, including its types, causes, symptoms, and treatments.

What are the types of asthma?

A woman sitting outdoors and using an inhaler
lakshmiprasad S/Getty Images

There are several types of asthma, including:

  • allergic asthma, which can be triggered by allergens like pollen or pet dander
  • exercise-induced asthma, which occurs during periods of increased physical activity
  • nocturnal asthma, or nighttime asthma, which occurs primarily during sleep
  • occupational asthma, or work-related asthma, which can be triggered by workplace substances like chemicals or metal shavings

According to the American Lung Association (ALA), asthma can also be classified according to how the inflammation associated with the condition occurs. For example, eosinophilic asthma involves white blood cells called eosinophils, which can proliferate and cause airway inflammation.

What causes asthma?

The exact cause of asthma isn’t well understood, but a combination of environmental and genetic factors may contribute Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source .

Asthma affects the bronchioles, which are small hollow passageways in the lungs. During an asthma attack, the bronchioles overreact to triggers and become inflamed, irritated, and swollen. This hinders the flow of air into the lungs and leads to asthma attack symptoms.

The smooth muscles surrounding the airways react by tightening Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source , further blocking airflow. Mucus production increases and makes it more difficult to breathe.

An illustration showing the physiological changes that occur in the airways during an asthma attack
During an asthma attack, the airways can become inflamed and constricted, making breathing difficult. Medical illustration by Jason Hoffman

Asthma triggers

Asthma triggers vary from person to person and season to season and can include:

  • air pollution
  • allergic reactions to allergens, such as:
    • pollen
    • dust
    • mold
    • animal dander
    • dust mites
  • cold air
  • excessive physical activity
  • infections, including colds and sinusitis
  • some medications, such as beta-blockers or aspirin
  • respiratory infections
  • stress
  • sulfites found in some foods, such as beer and seafood
  • tobacco smoke

What are the signs and symptoms of asthma?

You may experience asthma signs and symptoms daily or periodically. Any of these can be severe during an asthma attack and may include:

Learn more about 6 signs of uncontrolled asthma.

Serious symptoms that might indicate a life threatening condition

Severe asthma attacks can quickly progress from minor shortness of breath to a life threatening situation. Symptoms that require emergency medical attention include:

  • excessive anxiety
  • fast heart rate
  • pale or bluish coloration of the lips or fingernails
  • severe breathing difficulties

Learn what to do during a severe asthma attack.

How do doctors diagnose asthma?

Your doctor will ask about your symptoms and medical history to diagnose asthma. They will also perform a physical exam, which can involve evaluating your lungs, nose, and throat.

There are several lung function and breathing tests that doctors can order. These include:

Other potential tests include chest X-rays, blood tests, and allergy tests.

Learn more about diagnosing severe asthma.

What are the treatments for asthma?

Asthma treatment plans are individualized to the type and severity of your asthma.

Medications to treat asthma include long-term control medications and quick-relief “rescue” medications. Most asthma medications Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source work by reducing airway inflammation or opening the airways.

Long-term control asthma medications

Long-term control medications are meant to manage and prevent symptoms. They may come in inhaled, oral, or injectable forms. Below are some common examples. (Table)

Medication classExamples
immunomodulatorsomalizumab (Xolair), reslizumab (Cinqair)
corticosteroidsbudesonide (Pulmicort), flunisolide (Aerobid)
leukotriene modifiersmontelukast (Singulair), zafirlukast (Accolate)
long-acting beta-agonistsalbuterol (Proair), salmeterol (Advair)
methylxanthinestheophylline (Theo 24), dyphylline (Dilor)
long-acting anticholinergicstiotropium (Spririva)
combination medicationsbudesonide and formoterol (Symbicort)

Learn more about the types of medications that treat asthma.

Quick-relief asthma medications

“Rescue” or quick-relief medications treat acute symptoms and are generally inhaled through an inhaler. Rescue medications are used on the spot when a person feels a sudden onset of asthma symptoms.

Common fast-acting medications are listed below. (Table)

Medication classExamples
short-acting anticholinergicsipratropium (Atrovent)
corticosteroidsmethylprednisolone (Medrol)
short-acting beta-agonistslevalbuterol (Xopenex), pirbuterol (Mazair)
combination medicationsipratropium and albuterol (Combivent)

Learn more about asthma inhalers.

Bronchial thermoplasty

For severe asthma that doesn’t improve with medications, a bronchial thermoplasty may be beneficial. This procedure is performed under general anesthesia and involves applying heat to the airway muscles, which helps prevent them from narrowing and causing symptoms.

Learn more about asthma treatment options.

Lifestyle changes for asthma

In addition to medication, asthma treatment generally includes Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source reducing your exposure to triggers. This may involve:

  • avoiding cold air
  • avoiding or eliminating exposure to triggers like smoke, air pollution, or animal dander
  • eating a diet rich in fruits and vegetables
  • maintaining a moderate weight
  • quitting smoking if you smoke
  • reducing stress levels

Read more about 7 ways to ease asthma naturally.


Asthma is characterized by attacks that cause airway inflammation and narrowing, causing wheezing, coughing, and difficulty breathing. Though avoiding triggers may help prevent these attacks, many people also need medications to manage their symptoms.

Talk with your doctor about ways to manage asthma and prevent asthma attacks.

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Medical Reviewer: Adithya Cattamanchi, M.D.
Last Review Date: 2023 Jul 7
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