In this article

What is eosinophil count and percentage?

Eosinophils are a type of white blood cell that play a crucial role in your immune systemโ€™s response to parasitic infections, allergic reactions, and inflammatory conditions. These specialized cells are produced in the bone marrow and account for a small percentage of the total white blood cell count in healthy individuals. The eosinophil count measures the absolute number of eosinophils in your blood (measured in cells per microliter), while the eosinophil percentage reflects what proportion of your total white blood cells are eosinophils.

Why is eosinophil count and percentage important?

Monitoring your eosinophil levels provides valuable insight into your immune system function and can help identify various health conditions. Elevated eosinophil levels (eosinophilia) may indicate allergic diseases such as asthma or hay fever, parasitic infections, autoimmune disorders, certain cancers, or adverse drug reactions. Conversely, low eosinophil levels (eosinopenia) can occur during acute infections, with corticosteroid use, or in response to severe stress or illness.
Common symptoms associated with high eosinophil counts depend on the underlying cause but may include skin rashes, difficulty breathing, wheezing, runny nose, digestive issues, or fatigue. Because eosinophilia can be associated with serious conditions ranging from eosinophilic disorders to blood cancers, it is important to consult with your healthcare provider if your levels are abnormal.

How can I better understand my eosinophil count and percentage levels?

Eosinophil absolute count:

  • Normal: 30-350 cells/microL (or 0.03-0.35 x 10^9/L)
  • Mild eosinophilia: 350-1,500 cells/microL
  • Moderate eosinophilia: 1,500-5,000 cells/microL
  • Severe eosinophilia: >5,000 cells/microL

Eosinophil percentage:

  • Normal: 1-4% of total white blood cells
  • Elevated: >4% of total white blood cells
  • Low: <1% of total white blood cells

Eosinophil test results are typically analyzed as part of a complete blood count (CBC) with differential, which provides a comprehensive view of all your white blood cell types. Your healthcare provider will interpret your results in the context of your symptoms, medical history, and other laboratory findings to determine if further evaluation is needed.
It is worth noting that eosinophil levels can vary based on time of day, with levels typically being higher in the evening and lower in the morning. Factors such as stress, exercise, and certain medications can also influence eosinophil counts.

How can I maintain optimal eosinophil count and percentage levels?

If you need to address abnormal eosinophil levels, consider the following strategies in consultation with your healthcare provider:
Medical Management: If your eosinophil levels are elevated due to allergies, your doctor may recommend antihistamines, corticosteroids, or other allergy medications. For parasitic infections, antiparasitic medications will be prescribed. Treating the underlying condition is essential for normalizing eosinophil counts.
Lifestyle and Environmental Changes: Identifying and avoiding allergen triggers such as pollen, pet dander, dust mites, or certain foods can help reduce eosinophilia related to allergic conditions. Maintaining good hygiene practices and food safety can help prevent parasitic infections that elevate eosinophil counts.
Medication Review: Some medications can cause elevated eosinophils as a side effect. Work with your healthcare provider to review your medications and determine if any adjustments are necessary.

Where can I learn more?

DISCLAIMER: This information is for educational purposes only and is not a substitute for professional medical advice. Always consult your healthcare provider for interpretation of your eosinophil count results and for personalized health recommendations.