Causes & Risk Factors

Experts don't know exactly what causes asthma. But we do know that most people who have asthma also have allergies. Other risk factors include allergens, obesity, and chronic wheezing as a child.

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You may be more likely to have asthma if:

  • Someone in your family has asthma. Asthma may run in families (be inherited). If this is the case in your family, you may be more likely than other people to get long-lasting (chronic) inflammation in the airways.
  • You or someone in your family has an allergy. Most children and many adults with asthma have atopic dermatitis, allergies, or both. Asthma is much more common in people who have allergies, though not everyone with allergies gets asthma.
  • You had ongoing (chronic) wheezing when you were a child. Wheezing is a whistling noise of varying pitch and loudness that occurs when the small airways of the lungs become narrower because of inflammation or a buildup of mucus and dead cells in the airway.
  • Your airways overreact. People who inherit a tendency of the airways to overreact often get asthma.

Other things that may put you at risk for asthma include:

  • Cigarette smoking. People who smoke are more likely to get asthma than people who don't.
  • Cigarette smoking during pregnancy. This raises the risk of wheezing in babies. Babies whose mothers smoked during pregnancy also have worse lung function than those whose mothers didn't smoke.
  • Pollution. Environmental factors may play a role in the development of asthma. Some experts believe that there are more cases of asthma because of pollution.
  • Workplace irritants or allergens. Asthma in adults can be related to exposure to substances at work. This is called occupational asthma. Occupational asthma develops when a person is exposed to a particular inhaled substance in the workplace, such as wood dust, plastics, or chemicals.
  • Allergens. Studies show that exposure to allergens such as dust mites, cockroaches, and pet dander may influence asthma's development. Cockroach droppings in a child's home have been linked to a higher risk for asthma.
  • Obesity. Being obese raises your risk for asthma. Weight gain may make asthma worse.
  • You're a woman in your 40s. Women and men seem to have the same risk of getting asthma until they reach their 40s. After 40, women have a higher risk for asthma.

Your child may be at increased risk for very bad asthma attacks if he or she:

  • Is an infant with asthma symptoms.
  • Has a history of very bad symptoms, such as asthma attacks that get worse quickly and frequent nighttime symptoms.
  • Has a hard time taking medicines or often has to use quick-relief medicines (short-acting beta2-agonists) such as albuterol.
  • Has frequent changes in peak expiratory flow.
  • Has symptoms that last for a long time.
  • Doesn't use oral steroid medicines soon enough during an attack.
  • Doesn't have good support from family and friends.

Triggers, such as air pollution, pollen, pet dander, and colds and flu, also may make asthma worse and may lead to asthma attacks.

©2019 Healthwise, Incorporated. This information does not replace the advice of a doctor.

Causes & Risk Factors

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Prevention

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Complications

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Treatment

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Self-Care

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Causes & Risk Factors

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Prevention

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Symptoms & Diagnosis

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Complications

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Treatment

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Self-Care

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