Total White Blood Cell Count (WBC Count)

Why Is This Test Done?

Doctors may order a white blood cell count to check for infections (like bacterial or viral), inflammation, immune system issues, or blood disorders such as leukemia. It’s often part of a routine blood test or used to monitor conditions like cancer, autoimmune diseases, or after treatments like chemotherapy.

What to Expect Before the Test

No special preparation is needed for this test. You’ll have a small needle inserted into your arm or hand to draw a blood sample. It usually takes a few minutes, and you may feel a slight pinch. If you’re nervous, let your healthcare provider know—some people use numbing cream or choose a different vein.

What the Results Mean

A high WBC count might indicate an infection, inflammation, or a reactive immune response. A low WBC count could suggest immune suppression, bone marrow issues, or certain medications. Your doctor will interpret results in relation to your overall health and symptoms.

Possible Causes of Abnormal Results

Abnormal WBC counts can result from infections (like pneumonia or urinary tract infections), chronic illnesses (like diabetes or kidney disease), or medical treatments (like chemotherapy). Some conditions, such as autoimmune diseases or blood cancers, may also affect WBC levels.