Definition:
Eosinophils are a type of white blood cell that tends to increase with worsening asthma and other allergic conditions. Eosinophils normally help protect your body from foreign invaders such as bacteria, viruses, and parasites, but in asthma eosinophils release chemicals that lead to inflammation.
Eosinophils are produced in your bone marrow, but travel to other organs in your body when you are exposed to an asthma trigger. Re-exposure to an allergen leads to the release of chemicals like histamine that cause bronchoconstriction and asthma symptoms such as:
