Asthma Fact Sheet

Was this helpful?

What is asthma?

Asthma is a chronic lung disease. It interferes with regular lung function, making it difficult to breathe. The typical signs and symptoms of asthma—labored breathing, cough, chest tightness, and wheezing—are also common among other respiratory diseases. This can complicate the diagnosis. Asthma can develop at any age and for a multitude of reasons.

What are the different types of asthma?

"Asthma" is a general term. There are several types of asthma, each with a different cause or trigger:

  • Extrinsic asthma, or allergic asthma, is one of the most common types. It usually develops during childhood. Many different allergens can trigger extrinsic asthma.
  • Exercise-induced asthma occurs only during periods of increased physical activity.
  • Eosinophilic asthma is a rare and severe type. It is associated with increased swelling within the respiratory system due to higher counts of eosinophils. Esosinophils are a type of white blood cells.
  • Nocturnal asthma, or nighttime asthma, is a type that occurs primarily during sleep.
  • Occupational asthma, or work-related asthma, is triggered by substances at the workplace. This includes chemicals, metal shavings, and dust, among others.

There are also other subtypes and classifications. This includes intrinsic (nonallergic) asthma, cough-variant asthma, obesity-related asthma, steroid-resistant asthma, and adult-onset asthma.

Who gets asthma?

Asthma is a common condition worldwide. The World Health Organization estimates 235 million people have the disease. The most recent data for the United States show:

  • About 26 million people have asthma, including 6 million children younger than 18.
  • More women (nearly 10% of the population) than men (7%) have asthma.
  • Asthma rates are higher among African Americans (11.6%) than white Americans (8.3%) and Hispanic Americans (6.6%).
  • Asthma rates have been steadily rising, from 3.1% of the population in 1980 to 8.4% in 2016.

What are some conditions related to asthma?

Conditions with asthma or asthma-like symptoms include:

  • Allergic bronchopulmonary aspergillosis (ABPA)—an inflammatory reaction to the common mold, Aspergillus
  • Chronic cough syndrome—a cough lasting six weeks or longer, possibly due to more than one cause, such as a viral infection and allergies
  • Churg-Strauss syndrome (CSS)—also known as eosinophilic granulomatosis with polyarteritis (EGPA), CSS causes blood vessel inflammation in the lungs, skin, nerves and stomach
  • COPD (chronic obstructive pulmonary disease)—characterized by lung inflammation and permanent lung damage that blocks airflow

How does asthma affect quality of life?

Asthma reduces quality of life across all ages and genders. The harder it is to control the condition, the greater the impact. The limits asthma imposes on social activities and obligations also plays a large role.

Studies on the burden of asthma show:

  • 54% of children and 45% of adults with asthma report having asthma attacks.
  • Asthma contributes to nearly 11 million missed school days every year, and even more lost days of work.
  • Asthma was the main diagnosis for 11 million doctor office visits in 2014 and 1.7 million emergency room visits in 2015.
  • Asthma treatment costs per person per year are about $3,266. This includes prescription drugs, doctor visits, and hospital stays. Nationally, the economic cost of asthma—medical costs plus lost productivity—is $82 billion.

Can you die from asthma?

Asthma causes significant mortality around the world. In the United States, 3,518 people, including 209 children died of asthma in 2016. This is the most recent year for which data are available. African Americans die from asthma at a greater rate than white Americans.

What causes asthma?

In the most common type of asthma—allergic asthma—the underlying problem lies in a heightened immune response. The airways are very sensitive to allergens and the immune system sees the allergen as harmful and overreacts. The muscles around the airways tighten, and the tissues lining the airways swell and make extra mucus. Substances that directly irritate the lining of the airways can also trigger asthma.

Asthma is what the medical community calls multifactorial—many different genes and environmental factors interact in a complex way to cause asthma. Some of the genes are involved in the immune system or in how the lungs and airways function. Allergic asthma can run in families, supporting the role of genetic factors. The exact cause is not known.

Substances known to trigger asthma include:

  • Allergens, including animal dander, dust mites, cockroaches, pollen, mold, and certain foods and medications
  • Environmental factors and exposures including cold air, physical activity, and food additives
  • Infections including sinusitis and cold and flu viral infections
  • Irritants including tobacco smoke, odors from cleaning products, air pollutants like gas, fire smoke, and ash and dust particles

Known risk factors for asthma include:

  • Tobacco smoke exposure during both the prenatal and postnatal period
  • Prenatal exposure to poor diet or nutrition, and emotional stress in the mother
  • Childhood exposure to caregivers with high emotional stress
  • Male gender in children younger than 15, although after puberty, asthma tends to wane in males becoming more prevalent and severe in females
  • Working in occupations with exposure to chemicals, dust, fire, fumes, and many other damaging agents (about 15% of severe asthma cases are due to occupational triggers)

How are you diagnosed with asthma?

The main methods for diagnosing asthma are:

In children younger than five, a doctor may first prescribe an asthma medicine before ordering a breathing test. If symptoms improve, the child may have asthma.

What are common treatments for asthma?

Most asthma treatment plans involve lifestyle changes or accommodations to limit exposure to triggers. Plans combine this with medicines to control asthma symptoms.

Medicines include:

  • Long-term control medicines reduce inflammation and swelling and make the airways less sensitive. Inhaled corticosteroids and other medicines in this group help prevent asthma attacks.
  • Quick-relief medicines relieve asthma symptoms in case of an asthma attack or flare-up.

Lifestyle changes and accommodations for asthma and overall wellness include:

  • Avoiding irritants, allergens, and other triggers
  • Removing irritants or allergens from home, work or other surroundings
  • Stopping smoking if applicable (this includes people in the same household)
  • Treating conditions known to make asthma worse, such as emotional stress, allergies, and acid reflux
  • Having an asthma action plan explaining the patient’s medicines and purpose, symptom progression, and steps to take in an emergency

Additional asthma facts

More people each year and across the globe are developing asthma. However, increased awareness has led to earlier diagnosis and treatment. More treatment options have led to better symptom control and improved quality of life for millions of people with asthma.

May is National Asthma and Allergy Awareness Month, as declared by the Asthma and Allergy Foundation of America. Learn more about the Centers for Disease Control and Prevention’s National Asthma Control Program and asthma action plan resources.

Was this helpful?
Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2020 Sep 10
  1. Allergic Asthma. Genetics Home Reference.
  2. Asthma Diagnosis. Asthma and Allergy Foundation of America.
  3. Asthma Fact Sheet. National Medical Association.
  4. Definition of Aspergillosis. Centers for Disease Control and Prevention.
  5. Ginsberg D. An Unidentified Monster in the Bed – Assessing Nocturnal Asthma in Children. Mcgill J Med. 2009;12(1):31-38.
  6. Hossny E, Caraballo L, Casale T, et al. Severe Asthma and Quality of Life. World Allergy Organ J. 2017;10(1):28-35.
  7. Most Recent Asthma Data. Centers for Disease Control and Prevention.
  8. Nocturnal Asthma. National Jewish Health.
  9. Nurmagambetov T, Kuwahara R, Garbe P. The Economic Burden of Asthma in the United States, 2008-2013. Ann Am Thorac Soc. 2018;15(3):348-356.
  10. Occupational Asthma. Occupational Safety and Health Administration.
  11. Overview. American College of Allergy, Asthma & Immunology.
  12. Related Conditions. American Academy of Allergy, Asthma & Immunology.
  13. Severe Asthma Phenotypes. UpToDate. Stucky BD, Sherbourne CD, Edelen MO, et al. Understanding Asthma-Specific Quality of Life: Moving Beyond Asthma Symptoms and Severity. Eur Respir J. 2015;46(3):680-687.
  14. Subbarao P, Mandhane PJ, Sears MR. Asthma: Epidemiology, Etiology and Risk Factors. CMAJ. 2009;181(9):E181-190.
  15. Tools for Asthma Control. Centers for Disease Control and Prevention.
Explore Asthma
Recommended Reading
Health Spotlight
Next Up
Answers to Your Health Questions
Trending Videos