Contact Us | Patient Portal | Search:
Printer Friendly VersionEmail A FriendAdd ThisIncrease Text SizeDecrease Text Size

Blood differential

 

Definition

The blood differential test measures the percentage of each type of white blood cell (WBC) that you have in your blood. It also reveals if there are any abnormal or immature cells.

See also:

Alternative Names

Differential; White blood cell differential count

How the test is performed

The health care provider will take blood from your vein. The blood collects into an airtight container.

In infants or a young child, blood will be taken from a heel stick or finger stick. The blood is collected in a small glass tube or onto a slide or test strip.

Cotton or a bandage may be applied to stop any bleeding.

A laboratory specialist takes a drop of blood from your sample and smears it onto a glass slide. The smear is stained with a special dye, which helps tell the difference between various types of white blood cells.

Five types of white blood cells, also called leukocytes, normally appear in the blood:

  • Neutrophils
  • Lymphocytes (B cells and T cells)
  • Monocytes
  • Eosinophils
  • Basophils

A computer or the health care provider counts the number of each type of cell. The test shows if the number of cells are in proper proportion with one another, and if there is more or less of one cell type.

How to prepare for the test

No special preparation is necessary.

How the test will feel

When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.

Why the test is performed

This test is done to diagnose an infection, anemia, and leukemia. It may also be used to see if treatment for any of these conditions is working.

Normal Values
  • Neutrophils: 40% to 60%
  • Lymphocytes: 20% to 40%
  • Monocytes: 2% to 8%
  • Eosinophils: 1% to 4%
  • Basophils: 0.5% to 1%
  • Band (young neutrophil): 0% to 3%
What abnormal results mean

Any infection or acute stress increases your number of white blood cells. High white blood cell counts may be due to inflammation, an immune response, or blood diseases such as leukemia.

It is important to realize that an abnormal increase in one type of white blood cell can cause a decrease in the percentage of other types of white blood cells.

An increased percentage of neutrophils may be due to:

A decreased percentage of neutrophils may be due to:

An increased percentage of lymphocytes may be due to:

A decreased percentage of lymphocytes may be due to:

An increased percentage of monocytes may be due to:

  • Chronic inflammatory disease
  • Parasitic infection
  • Tuberculosis
  • Viral infection (for example, infectious mononucleosis, mumps, measles)

An increased percentage of eosinophils may be due to:

A decreased percentage of basophils may be due to:

  • Acute allergic reaction
What the risks are

There is very little risk involved with having your blood taken. Veins and arteries vary in size from one patient to another and from one side of the body to the other. Taking blood from some people may be more difficult than from others.

Other risks associated with having blood drawn are slight but may include:

  • Excessive bleeding
  • Fainting or feeling light-headed
  • Hematoma (blood accumulating under the skin)
  • Infection (a slight risk any time the skin is broken)
References

Bagby GC. Leukopenia and leukocytosis. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 173.


Review Date: 2/23/2009
Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial policy, editorial process and privacy policy. A.D.A.M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).
The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- 2009 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.
MAIMONIDES
MEDICAL CENTER


Home Page
Why Choose Us
Donations
Website Terms of Use
PATIENT
INFORMATION


Visitor & Patient Info
Patient Portal
We Speak Your Language
Patient Privacy
Contact Us
KEY
INFORMATION


Find a Physician
Medical Services
Maimonides In the News
Directions & Parking
FOR HEALTH
PROFESSIONALS


Medical Education
Career Opportunities
Nurses & Physicians
Staff Intranet Access

Maimonides Medical Center    |    4802 Tenth Avenue    |    Brooklyn, NY 11219    |    718.283.6000