Published:
April 26, 2022
A complete blood count and differential (CBC/DIFF) is one of the most common blood tests. Your health-care provider may order this test as part of a routine checkup, to monitor a health condition, or when you’re not feeling well, to try to figure out why.
This one test offers a wealth of information, ranging from your body’s ability to fight infection, possible nutritional deficiencies, and how well you can respond to an injury with blood clotting. It can also show evidence of anemia or a cancer like leukemia.
The terminology and abbreviations can be confusing. Let’s break it down.
Breaking Down a CBC/DIFF
A CBC/DIFF test measures many different parts of your blood—red blood cells, white blood cells, and platelets.
WBC (White blood count)
If this result is low, it may show a problem such as a bone marrow disorder and decreased ability to fight infection. If elevated, it could indicate a response to an infection. If greatly increased, could indicate a blood cancer such as leukemia.
Red Blood Cells
These measurements show different characteristics of your body’s red blood cells. They can indicate that you have a low blood count (anemia) and if anemic—what dietary deficiency that may be contributing to your anemia. They also give information to your provider about hereditary disorders that affect blood cells, such as thalassemia, a condition that causes your body to have less hemoglobin than normal.
- RBC (Red blood count)
- HGB (hemoglobin)
- HCT (hematocrit)
- MCV (mean corpuscular volume)
- MCH (mean corpuscular hemoglobin)
- MCHC (mean corpuscular hemoglobin concentration)
Platelet Count (PLC)
Platelets, are the smallest type of blood cell and one of the main components in your body’s ability to clot, which stops bleeding when you are injured. If there are too few platelets, uncontrolled bleeding may be a problem. If there are too many platelets, there is a chance of a blood clot forming in a blood vessel. Platelets may also be involved in hardening of the arteries (atherosclerosis).
Differential (DIFF)
This component of the CBC/DIFF breaks down the different forms of white blood cells that make up your immune response to infections. The main cells present, in order of frequency, are neutrophils (fight bacterial infections), lymphocytes (seen more in viral and long-term immune responses), monocytes (fight both bacterial, viral and fungal infections) and eosinophils (increased in allergic reactions).
Understanding Your Blood Test Results
The best source for understanding your individual blood test results is your health-care provider. Your provider looks at your overall medical history and can advise on any next steps that may be needed.
The National Institutes of Health’s Heart, Lung and Blood Institute provides some normal adult ranges for the different parts of the CBC/DIFF test. Test results in your MyLGHealth patient portal also show normal ranges. But again, many factors can contribute to your results. The best person to answer your questions is your provider.
Penn Medicine Lancaster General Health offers laboratory testing facilities in Lancaster, Lebanon and Chester counties. You can find a location convenient for you and schedule your blood test online.