When someone is allergic to something, his or her immune system responds to the exposure to it as if it were harmful to the body. The immune system releases antibodies, and histamines are released into the blood. The histamines trigger the symptoms usually associated with allergies, such as itchy eyes.

Asthma, meanwhile, is a chronic lung condition that constricts breathing. The lung passages are inflamed, limiting the amount of oxygen the airways can carry. When a person with asthma is exposed to certain triggers, those airways constrict even more and fill with mucous, causing coughing, wheezing, shortness of breath, chest tightness, pain and pressure.

If you suspect that you have either of these conditions, speak to your doctor about diagnosis and treatment.

The exact cause of asthma is unknown, but there are a variety of factors associated with it:

  • Asthma tends to run in families. If you have a parent with asthma, you are much more likely to develop it than if you do not have a parent with asthma.
  • Pregnant women who smoke have children who are more likely to have asthma. In addition, children who have certain respiratory problems may have an increased risk of developing the condition.
  • People who have certain allergies, including hay fever, are at risk for developing asthma.
  • Children and adults who are overweight have an increased asthma risk.
  • Exposure to certain chemicals, fumes and dusts may cause asthma. One such irritant is cigarette smoke.

Sources: American Lung Association, WebMD®