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Causes and Triggers


Lt Col Reynolds
Although asthma affects millions of people in the United States, researchers still don't know what causes it. People with asthma can be of any race, age, or sex, but there are some factors that may increase the risk of developing asthma.

For example, family history may influence the likelihood of developing asthma. If other people in your family have asthma or other allergic diseases, you are more likely to develop asthma. Another risk factor is being exposed early in life to things like tobacco smoke, infections, and some allergens. Other health problems, such as obesity, may also be linked to asthma.

Asthma can develop at any age, but in people younger than 30, asthma is most commonly triggered by allergies. For some people with asthma, especially older adults, respiratory allergies don't seem to play a role. Instead, exposure to any irritant — such as viruses, cigarette smoke, cold air, and even emotional stress — can trigger an asthma attack.

These allergens and irritants are called triggers, and they vary from one person to another. In every case, it's important to avoid known triggers in order to reduce airway inflammation and asthma symptoms.

Common asthma triggers include:

  • Allergens, such as pollen, cockroaches, and molds
  • Air pollutants and irritants
  • Smoking and secondhand smoke
  • Respiratory infections, including the common cold
  • Physical exertion, including exercise
  • Cold air
  • Certain medications, including beta blockers, aspirin, and other non-steroidal anti-inflammatory drugs, or NSAIDs
  • Sulfites, which are preservatives added to some perishable foods
  • Gastroesophageal reflux disease, or GERD, and
  • Sinusitis

You can find out more about many of these triggers in this section.

Providers can help patients figure out what their asthma triggers might be. Part of a good asthma management plan is taking steps to reduce exposure to known asthma triggers.