A Complete Blood Count (CBC) is a common blood test used to evaluate your overall health and detect a wide range of disorders, including infections, anemia, and certain cancers. It measures different components of your blood.
What the CBC Test Measures
1. Red Blood Cells (RBCs)
These carry oxygen from your lungs to the rest of your body. Low levels may indicate anemia.
2. Hemoglobin (Hb or Hgb)
This is the protein in red blood cells that carries oxygen. It helps check for anemia or other blood disorders.
3. Hematocrit (Hct)
This shows the percentage of your blood made up of red blood cells.
4. White Blood Cells (WBCs)
These help fight infection. High or low counts may signal infection, inflammation, or immune system issues.
5. Platelets
These help with blood clotting. Too few can cause bleeding problems; too many may increase the risk of blood clots.
6. Mean Corpuscular Volume (MCV)
This measures the average size of red blood cells and helps classify types of anemia.
Why a CBC Is Done
- To investigate symptoms like fatigue, weakness, fever, or bruising
- To check for infections or inflammation
- To diagnose blood disorders like anemia, leukemia, or clotting issues
- To monitor the effects of medications or ongoing medical conditions
Preparation and Procedure
- No special preparation is usually needed
- A blood sample is taken from a vein in your arm
- Results are usually available within a day
When to See a Doctor
If your CBC results are abnormal, your doctor may recommend further testing to find the cause.