Asthma is a chronic condition in which the airways of the lungs become narrow, inflamed, and filled with mucus.
These airway issues produce symptoms like trouble breathing, wheezing, and coughing. For some people, these symptoms show up only in response to specific triggers — stuff like pollen or other allergens, exercise, or even weather changes. In others, asthma symptoms flare up during sleep or on a daily basis.
There are different categories of asthma, most of which are defined by their triggers or symptoms. For example, nocturnal asthma is a type that comes on at night while a person is in bed, whereas occupational asthma is caused by exposure to certain chemicals or pollutants at work.
RELATED: What Type of Asthma Do I Have?
Experts say it’s often impossible to know exactly why a person develops asthma. “The disease pathways are complicated,” says Patricia Takach, MD, an associate professor of clinical medicine in the section of allergy and immunology at the University of Pennsylvania’s Perelman School of Medicine. For example, Dr. Takach says, allergy-induced asthma seems to stem from a combination of genetic and environmental factors.
There’s evidence that air pollution promotes the development of asthma. (2) And there’s also research linking some consumer chemicals to increases in asthma rates. (3) But none of these theories have been proved, and experts usually can’t explain why one person develops asthma and another does not.
These Are the Most Common Risk Factors for Asthma
The underlying reasons why these factors are linked to asthma (whether it's that one causes the other or there's just a correlation) are not well understood. But each of these factors is associated with a greater likelihood of developing the condition (4,5).
- Smoking Tobacco It’s not clear whether smoking actually causes asthma to develop in the first place; studies that have examined this association have come up with mixed results. (6) But smoking is associated with a heightened risk for asthma symptoms. There’s also some early evidence that vaping and e-cigarettes may raise a person’s asthma risk. (7)
- Family History of Asthma If one of your parents has asthma, you’re up to six times more likely to develop the disease than someone who doesn’t have a parent with asthma. (5)
- Childhood Infections People who experience viral respiratory infections during childhood may be more likely to develop asthma later in life. (5)
- Workplace Exposures Working with chemicals, mold, dust, cleaning products, and anything that emits gases or vapors may increase your risk of developing asthma. Jobs in hairdressing, agriculture, and manufacturing are all types that can expose you to heightened asthma risk. (5)
- Allergies If you have allergies, your risk for asthma is higher compared with someone who does not have allergies. (4)
- Exposure to Air Pollution If you live near a busy roadway or you spend a lot of time sitting in heavy traffic, those and other air pollution exposures may increase your risk for asthma. (4)
- Obesity Adults and kids who are obese suffer from much higher rates of asthma than those who are not obese. (5)
These Are the Most Common Asthma Triggers
Among those who have asthma, symptoms present in various ways and for some more often than for others. While some people experience asthma symptoms on a daily basis, others have symptoms only when they encounter specific triggers.
Some common asthma triggers are: (4,8)
- Airborne allergens or irritants, including dust, pollen, mold, and pet hair
- Infections, including the flu, sinusitis, and, in some cases, upper respiratory tract infections
- Smoke or chemical fumes
- Cold air
- Some medication, including beta-blockers, aspirin, ibuprofen, and naproxen
- Food additives, including sulfites and other preservatives
- Strong emotions and stress
- Other medical conditions, including gastroesophageal reflux disease (GERD)
- Crying or laughing
There Are Ways to Prevent Asthma Flare-ups
If you have asthma, your doctor can help you identify and avoid the triggers that cause your flare-ups. Apart from avoiding these triggers and taking your medication as your doctor instructs, there are other ways to prevent flare-ups from happening, which include: (4,9)
- Get vaccinated against the flu and pneumonia. These conditions can trigger asthma. Getting vaccinated can lower your odds of contracting one of them.
- Learn to monitor your breathing. Using a peak airflow meter at home can help you spot signs of an impending attack before it starts. This can give you time to take your medication or calm yourself down before a full-blown asthma attack strikes.
- Spot warning signs. A slight cough, problems breathing at night, and increased use of an inhaler are all warning signs of an impending asthma attack. Keep an eye out for these, and let your doctor know if you think an attack is imminent.
- Practice mindful breathing. Stress and anxiety are asthma triggers in some. Learning to manage these mental states with calming breathing techniques can help you avoid an attack.
If You Don’t Have Asthma, You May Be Able to Lower Your Risk for Developing It in the Future
Obesity is a major risk factor for adult-onset asthma, which is a type that develops after childhood. Maintaining a healthy weight by eating a healthy diet and regularly exercising could lower your risk for developing asthma later on.
Breathing in irritants or allergens like tobacco smoke, mold, chemicals, pesticides, or other types of air pollution could also trigger the emergence (or reemergence) of asthma. Avoid these whenever possible. (10)
“Asthma has been on the rise for a number of years, and air pollution is one hypothesis as to why,” says Emily Pennington, MD, a pulmonologist and asthma specialist at the Cleveland Clinic. But the precise underlying drivers of asthma formation remain mysterious.
Editorial Sources and Fact-Checking
- Hygiene Hypothesis: Early Germ Exposure Prevents Asthma? Mayo Clinic.
- Air Pollution. Asthma and Allergy Foundation of America. October 2015.
- Vincent MJ, Bernstein J, Basketter D, et al. Chemical-Induced Asthma and the Role of Clinical, Toxicological, Exposure, and Epidemiological Research in Regulatory and Hazard Characterization Approaches. Regulatory Toxicology and Pharmacology. November 2017.
- Asthma: Symptoms and Causes. Mayo Clinic.
- Asthma Risk Factors. American Lung Association.
- Thomson NC, Chaudhuri R, Livingston E. Asthma and Cigarette Smoking. European Respiratory Journal. 2004.
- The Impact of E-Cigarettes on the Lung. American Lung Association.
- Asthma Attack. American College of Allergy, Asthma, & Immunology.
- How Do I Prevent an Asthma Attack? American College of Allergy, Asthma, & Immunology.
- Adult Onset Asthma. Asthma and Allergy Foundation of America.