Asthma and your health


What is asthma?

Asthma is a disease that causes the airways of the lungs to become swollen, fill with fluid and tighten. Asthma causes repeated episodes of wheezing, breathlessness, chest tightness, and nighttime or early morning coughing. If you have asthma, you have it all the time, but asthma attacks only when something bothers (triggers) your lungs. Asthma can be controlled by taking medicine and avoiding the triggers that can cause an attack. You must remove the triggers in your environment that can make your asthma worse or cause an attack.

Why is asthma a concern?

Asthma is one of the most common long-term diseases in children, but many adults have asthma, too.

Every day in the United States, approximately1:

  • 34,400 people have an asthma attack.

  • 4,700 people visit the emergency room due to asthma.

  • 1,200 people are admitted to the hospital due to asthma.

  • 10 people die due to asthma.

Asthma often causes a lower quality of life for children who have it and the people who care for them. Asthma is associated with undesirable health outcomes that could be prevented, such as obesity.

There are also large direct and indirect economic costs, including hospitalization, medications and time off from school or work.

Who is at risk2?

  • In adults, women are more likely to have asthma than men.

  • In children, boys are more likely to have asthma than girls.

  • Adults ages 18 to 24 are more likely to have asthma than older adults.

  • Adults who are African American or multiracial are more likely to have asthma than white adults.

  • African American children are 2 times more likely to have asthma than white children.

  • Adults who didn’t finish high school are more likely to have asthma than adults who graduated high school or college.

  • Adults with an annual household income of $75,000 or less are more likely to have asthma than adults with higher incomes.

  • Smokers are more likely to have asthma than non-smokers.

  • Adults with obesity are most likely to have asthma.

  • Increase risk during high exposure events like wildfires.

Important asthma triggers are3:
  • Environmental tobacco smoke, also known as secondhand smoke.

  • Dust mites.

  • Outdoor air pollution.

  • Cockroach allergen.

  • Pets.

  • Mold.

  • Strenuous physical exercise.

  • Some medicines.

  • Bad weather, such as thunderstorms, high humidity, or freezing temperatures.

  • Some foods and food additives

  • Strong emotional states that can lead to hyperventilation and an asthma attack.

What is known about asthma and the outdoor environment?

Recent studies have linked outdoor environmental factors to increased or worsening asthma outcomes4, including:

  • Exposure to traffic-related air pollution (including carbon monoxide, nitrogen dioxide and sulfur dioxide).

  • Chronic exposure to ground-level ozone, or particulate matter (especially, PM 2.5).

  • Allergens, such as pollen, mold, or mildew.

When and where is outdoor air pollution the worst?
  • Ground-level ozone is often worst on hot summer days, especially in the afternoons and early evenings.

  • Particulate matter pollution (e.g., haze, smoke, and dust) can be bad during any time of year, even in winter. It can be especially bad when the weather is calm, allowing air pollution to build up. Additionally, it can be bad around factories and when smoke is in the air from wood stoves or burning vegetation.

  • Traffic-related air pollution can be high near busy roads or highways and during rush hour.

What is known about asthma and the indoor environment?

Recent studies have also linked several indoor environmental factors to increased or worsening asthma outcomes, including:

  • Particulate matter generated from indoor sources (such as cooking exhaust, wood-burning stoves and fireplaces, and cleaning activities that re-suspend particles).

  • Indoor sources of nitrogen dioxide, including gas stoves, space heaters, furnaces, and fireplaces.

  • Second-hand tobacco smoke.

  • Indoor allergens such as mice, cockroaches, and dust mites.

  • Indoor sources of mold or mildew.

Other factors that research has shown to be associated with asthma2,4:
  • Infections, such as a cold or the flu.

  • Urbanization.

  • Race/ethnicity.

  • Socioeconomic status.

How can risk be reduced?

Asthma has no cure, but it can be controlled. The majority of problems associated with asthma are preventable if asthma is managed according to established guidelines.

People can take steps to help protect their health from air pollution. They should:

  • Know how sensitive they are to air pollution.

  • Know when and where air pollution may be bad.

  • Plan activities when and where pollution levels are lower, using the Air Quality Index to guide planning.

  • Change their activity level.

  • Listen to their bodies.

  • Keep quick-relief medicine on hand when they're active outdoors.

  • Follow an asthma action plan with the help of their health care provider.

How is asthma tracked?

The Tracking Network uses data on hospitalizations and emergency department visits due to asthma. Because the Tracking Network uses hospital and emergency department data to calculate measures, it reflects more severe cases of asthma. Being hospitalized for asthma usually means a person has a more severe case than someone with symptoms who isn't hospitalized.

  1. U.S. Centers for Disease Control and Prevention, National Center for Environmental Health. Most Recent Asthma Data. 2018. https://www.cdc.gov/asthma/most_recent_data.htm. Updated May 15, 2018.

  2. U.S. Centers for Disease Control and Prevention, National Center for Environmental Health. Health Effects Asthma and the Environment. https://ephtracking.cdc.gov/showAsthmaAndEnv. Updated December 14, 2016.

  3. Pollock J, Shi L, Gimbel RW. Outdoor Environment and Pediatric Asthma: An Update on the Evidence from North America. Canadian Respiratory Journal. 2017, 2017:1-16. doi:10.1155/2017/8921917.

  4. Ahluwalia SK, Matsui EC. The indoor environment and its effects on childhood asthma. Current Opinion in Allergy and Clinical Immunology. 2011, 11(2):137-143. doi:10.1097/aci.0b013e3283445921.