Eosinophilia is a medical condition characterized by an elevated level of eosinophils, a type of white blood cell, in the bloodstream. Eosinophils play a crucial role in the immune system, particularly in fighting off parasitic infections and responding to allergens. Normal eosinophil levels are typically low, but various factors can cause an increase, including allergies, infections, and certain diseases. The condition can be diagnosed through a blood test that measures eosinophil counts. Symptoms may vary depending on the underlying cause and can include skin rashes, respiratory issues, or gastrointestinal problems. Treatment focuses on addressing the underlying condition that is causing the eosinophilia.