Illustration of a boy using an asthma inhaler

What Is Asthma?

Asthma is a chronic lung disease that causes the airways to become inflamed and narrowed, making breathing difficult. An estimated 262 million people worldwide live with asthma, which can affect people of all ages.

Though research has not yet confirmed the exact cause of asthma, a combination of genetic and environmental factors likely play a role. Asthma symptoms are often triggered by allergens, respiratory infections, and exercise. Common symptoms include shortness of breath, wheezing, coughing, and chest tightness. Diagnosing asthma involves a physical examination, medical history review, lung function tests, and allergy testing.

Though asthma can have a major impact on your life, there are many effective medications and lifestyle modifications that can help control symptoms and prevent asthma attacks (a sudden, potentially life-threatening worsening of asthma symptoms).


There are many types of asthma, which are classified based on the underlying cause and triggers of the condition. Understanding your asthma type can help your healthcare provider develop an individualized treatment plan to help keep your asthma well-controlled.

The most common asthma types include: 

  • Allergic: Triggered by exposure to allergens such as dust mites, pollen, and pet dander
  • Non-allergic: Triggered by irritants such as smoke, pollution, cold air, or respiratory infections
  • Occupational: Caused by long-term exposure to harmful irritants in the workplace, such as chemicals, dust, or fumes
  • Exercise-induced bronchoconstriction: Triggered by physical activity due to losing heat and/or water during exercise
  • Pediatric: Begins in childhood and is usually caused by genetic and environmental factors

It is possible for your asthma to encompass multiple types.

Asthma Symptoms 

Asthma affects everyone differently. Some people may have occasional mild symptoms, while others may have severe symptoms that impact their day-to-day life. Common asthma symptoms include:

  • Shortness of breath: This is usually characterized as difficulty breathing or a sense of “air hunger." It may feel like something heavy is sitting on your chest, making it difficult to take full, deep breaths.
  • Wheezing: This is a high-pitched, whistling sound most often heard when exhaling. 
  • Coughing: A persistent cough may be dry or wet (with mucus/sputum) and is often worse at night and in the mornings.
  • Chest tightness: This is a feeling of pressure, tightness, or squeezing around the chest. A dull ache or sharp, stabbing pain may accompany chest tightness. 

What Causes Asthma? 

When you have asthma, certain triggers cause inflammation, which makes the airways swollen and narrow. Muscles around the airways tighten and constrict, and the body may produce excess mucus. These factors prevent normal airflow in and out of the lungs.

The exact cause of asthma is unknown, but research suggests genetic and environmental factors play a role. Certain factors linked to the development of asthma include:

  • Environment: Allergens, such as pet dander, mold, pollen, and dust mites, have been linked to asthma. Lung irritants, including cigarette smoke and air pollution, are also linked to the condition. 
  • Family history: Asthma runs in families, and having a family member with the condition increases your risk.
  • Viral infections: Viral and bacterial respiratory infections (e.g., common cold, influenza) in infancy and early childhood can affect lung and immune system development and lead to asthma.

Certain risk factors can increase your risk of developing asthma:

  • Having allergies or eczema 
  • Smoking
  • Exposure to secondhand smoke or air pollution
  • Occupational exposure to lung irritants or chemicals
  • Obesity
  • Low birth weight or premature birth
  • Biological sex: In childhood, asthma is more common in boys, but more adult women have asthma than men, which suggests female sex hormones may play a role.


An asthma diagnosis is based on your symptoms, medical and family history, and diagnostic test results. To diagnose asthma, your healthcare provider will ask about your symptoms, including what triggers or worsens them and how often they occur.

Your healthcare provider will thoroughly evaluate your medical history, including a family history of asthma and allergies, and perform a physical exam to look for signs and symptoms of asthma. They may listen to your lungs to check for wheezing and watch you breathe to look for shallow or rapid breathing. If your healthcare provider suspects you have asthma, they will order diagnostic tests to confirm the diagnosis. You may be referred to an allergist (a doctor who specializes in allergic diseases) and/or a pulmonologist (a doctor who specializes in the lungs).

Tests commonly used to diagnose asthma include:

  • Spirometry: A lung function test that measures how much and how quickly you can exhale after taking a deep breath.
  • Peak flow meter test: A small handheld device that measures how much air you can breathe out at once.
  • Bronchial provocation test: Measures the sensitivity of the airways to triggers and irritants. 
  • FeNO test: Measures the amount of nitric oxide (NO) in the breath. High levels of NO can indicate airway inflammation.
  • Allergy testing: Skin prick or blood allergy tests help identify specific allergens that may trigger asthma symptoms.

Treatments for Asthma  

There is no cure for asthma, but asthma treatments can effectively control symptoms and reduce the frequency and severity of asthma attacks. Asthma treatment usually includes medications and lifestyle modifications. 


Asthma medications help reduce inflammation and relax the muscles around the airways to keep the airways open and control symptoms. Medicines may be breathed in through an inhaler or nebulizer, taken orally as capsules or liquid, or given through injection or infusion. 

 Medications used to treat asthma include:

  • Quick-relief medications: Also known as rescue medicines, quick-release medications rapidly open the airways. These are taken when you first notice symptoms or your symptoms are worsening to help prevent asthma attacks.
  • Controller medications: These medications are taken daily to reduce inflammation and swelling, relax muscles around the airways to keep them open, and decrease mucus production. 
  • Combination medications: These are what the name implies: a combination of quick-relief and controller medications in one inhaler to provide short-term relief and long-term control of symptoms. 
  • Biologics: These are more powerful drugs that target specific immune cells or proteins linked to inflammation in the airways to help keep the airways open and reduce symptoms.
  • Immunotherapy (commonly called allergy shots): This is a long-term therapy that involves exposure to small amounts of allergens, gradually increasing the dose over time to desensitize the immune system and reduce your sensitivity to the allergen. 

Lifestyle Modifications 

Lifestyle modifications are an essential component of asthma management. Making healthy lifestyle choices can help control symptoms and reduce the frequency of asthma attacks.

  • Avoiding triggers: Once you know what triggers your asthma, such as allergens or lung irritants, it is important to avoid them when possible. Depending on your triggers, this may mean staying indoors on high pollen days, quitting smoking, or avoiding close contact with people with respiratory infections. 
  • Exercise: Regular physical activity can help improve lung function and support your overall health. If exercise worsens your asthma symptoms, consider low-impact exercises such as walking, cycling, or yoga.
  • Weight management: Maintaining a healthy body weight can help boost the effectiveness of medications, reduce symptoms, and lower the risk of asthma attacks.
  • Stress management: Strong emotions and stress can trigger or worsen asthma symptoms. Finding ways to manage and reduce stress, such as meditation, breathing exercises, getting good sleep, and making time for self-care can help prevent asthma attacks.

How to Prevent Asthma Attacks

There is no guaranteed way to prevent asthma, but there are things you can do to reduce the frequency and severity of asthma attacks. 

Asthma Action Plan 

Once you are diagnosed with asthma, you and your healthcare will work together to develop an asthma action plan (AAP). Your AAP is designed to help you recognize when your symptoms worsen and outline the appropriate steps to prevent an asthma attack. Your AAP may also include:

  • What triggers your symptoms
  • Your medications and how and when to take them 
  • When to seek emergency care when symptoms become severe 
  • Your peak flow monitor baseline results

Use a Peak Flow Meter

A peak flow meter is a small handheld device you blow into to measure how well air moves out of your lungs. Using a peak flow meter regularly can help monitor your lung function and measure the narrowing of your airways hours or days before asthma symptoms occur. Your peak flow readings can warn you when you need your quick-relief medications and help identify when your asthma is not well-controlled. 

Comorbid Conditions   

Certain health conditions can worsen your asthma symptoms and make them more difficult to manage. These are known as comorbid conditions, and many people with asthma may have one or more of the following:

  • Allergies: Allergic reactions to certain substances, such as pollen, pet dander, mold, or foods, can increase the risk of asthma and trigger asthma symptoms. 
  • Chronic obstructive pulmonary disease (COPD): A chronic lung disease that shares many symptoms with asthma, including difficulty breathing and coughing. 
  • Rhinitis: Inflammation of the nose causes excess mucus production that drips down the back of the throat (postnasal drip). Postnasal drip can irritate the airways and worsen asthma symptoms. 
  • Gastroesophageal reflux disease (GERD): With GERD, stomach contents flow back up into the esophagus and can cause heartburn and coughing and trigger asthma symptoms.
  • Obstructive sleep apnea: This is a sleep disorder characterized by breathing disruptions during sleep. Sleep apnea shares risk factors with asthma; both conditions can exacerbate the other. 
  • Sinusitis: This is characterized by inflammation or infection of the sinuses that leads to increased mucus production and plugged-up sinuses, which can trigger asthma symptoms.  

Living With Asthma

Living with asthma can impact every part of your life—you may feel hesitant to participate in activities you once enjoyed or exhausted from the extra planning it takes to avoid triggers and prevent flare-ups. Whether your asthma is mild or severe, proper asthma management is key to living well with the condition.

Work with your healthcare provider to develop your asthma action plan and ensure you have the right treatments to control your symptoms. Regular check-ups with your healthcare provider are important for monitoring your lung function and adjusting treatment. With the right treatments and lifestyle modifications, most people with asthma can live full and active lives.

Was this page helpful?
13 Sources uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. MedlinePlus. Asthma.

  2. World Health Organization. Asthma.

  3. American College of Allergy, Asthma and Immunology. Types of asthma.

  4. Asthma and Allergy Foundation of America. Asthma symptoms.

  5. National Heart, Lung, and Blood Institute. Asthma causes and triggers.

  6. Kuruvilla ME, Vanijcharoenkarn K, Shih JA, Lee FEH. Epidemiology and risk factors for asthma. Respiratory Medicine. 2019;149:16-22. doi:10.1016/j.rmed.2019.01.014

  7.  Asthma and Allergy Foundation of America. Asthma diagnosis.

  8. American Academy of Asthma, Allergy and Immunology. What is a FeNO test?.

  9. Asthma and Allergy Foundation of America. How is asthma treated?

  10. Allergy and Asthma Network. Lifestyle changes to manage asthma.

  11. National Heart, Lung and Blood Institute. Asthma treatment and action plan.

  12. Asthma and Allergy Foundation of America. Peak flow meters.

  13. Asthma and Allergy Foundation of America. Other health conditions.

Related Articles