White blood cells are an important part of your body’s immune system. They are vital for protecting you from invading bacteria or parasites. Your body is host to five different kinds of white blood cells, all of which are made in the bone marrow.
Each white blood cell lives for three to four days, then is replaced. How many white blood cells and what type you have in your body can give doctors a better understanding of your health. Elevated levels of white blood cells in your blood are a good indicator that you are suffering from an illness. This is because it means your body is sending more and more white blood cells to fight off infections.
An eosinophil count is a type of blood test that measures the quantity of eosinophils (a type of white blood cell) in your body. An eosinophil count is typically used to confirm a diagnosis rather than make a diagnosis. According to the American Association of Clinical Chemistry, eosinophils are particularly involved in immune responses to infections caused by parasites and allergic reactions (AACC, 2012).
Eosinophils have two distinct functions in your immune system. First, they destroy invading germs like viruses, bacteria, or parasites such as Giardia and pinworm. Eosinophils also create an inflammatory response.
Inflammation is both good and bad. It helps isolate and control the immune response at the site of an infection, but it also damages the tissue around it. Allergies are immune responses that often involve chronic inflammation. Eosinophils play a significant role in the inflammation related to allergies and asthma.