CBC with Auto Diff in the Knoxville Region

A complete blood count -- often called a CBC -- is a blood test that can help your doctor understand your overall health and potentially find signs of a number of disorders.

A CBC can be used as a screening test to check for conditions that affect blood cells before symptoms show, and is often done as part of a routine physical. Your doctor may also recommend a CBC if you display symptoms such as fatigue, fever or unusual bruising. Some of these symptoms could suggest issues like anemia or infection. A CBC can also check for immune system issues or blood cancers.

The test might also be done to monitor a medical condition, or check to see how medicines are working.

Your doctor may recommend other blood tests in addition to a CBC, including a comprehensive metabolic panel, which provides information about the levels of sugar and proteins in your blood and about your body's electrolytes.

Little preparation is needed for a CBC. Unlike some blood tests, a CBC does not usually require you to avoid eating or drinking for a period before the test. Your doctor will provide you with any special instructions, if needed.

A medical provider — often a nurse or an expert called a phlebotomist — will insert a needle in a vein, usually in your arm. The medical provider may tie a rubber strap around your upper arm and ask you to make a fist with your hand. This allows a vein in your arm to expand slightly and allows for easier insertion of the needle.

You may feel a small prick or pinch. But the process is not uncomfortable for most people.

Blood is collected into a small vial from a flexible tube connected to the needle.

The needle is then removed and you'll be given a bandage to press on the area where the needle was inserted to stop any bleeding. The entire process usually takes two minutes or less.

Your provider then sends the sample to a lab to analyze it.

A CBC measures components of your blood and the proportion of those components, including:

• Red blood cells: carry oxygen throughout your body
• White blood cells: fight infections
• Hemoglobin: the protein in red blood cells that helps carry oxygen throughout your body
• Platelets: help your blood clot
• Hematocrit: the proportion of red blood cells in your blood to your total volume of blood

A CBC also normally measures other chemicals and substances in your blood -- all of which can give your doctor signs of any underlying health problems.

A CBC test result can point to a range of health issues:

• Unusually low or high levels of red blood cells or hemoglobin, or unusual hematocrit percentage levels, could suggest anemia or heart disease, among other issues.
• An unusually high white blood cell count could suggest inflammation or an infection. A low white blood cell count could suggest an autoimmune problem, or cancer.
• A low or high platelet count could be signs of other medical issues, or could result from medicines you're taking.

Other possible issues that might be highlighted by a CBC test include:

• dehydration
• vitamin or mineral deficiencies
• side effects from chemotherapy, antibiotics or any of a number of medicines

No. An unusual result in a CBC does not necessarily mean you have a medical issue that needs treatment. Your doctor will consider the results along with other symptoms you may be experiencing and your medical history. If a CBC shows something unusual, your doctor may recommend other lab tests, blood tests or other diagnostic tests to explore further.

There is almost no risk to a CBC. There may be minor bruising in the area of the needle stick, but that almost always disappears quickly.

Sources:
https://www.mayoclinic.org/tests-procedures/complete-blood-count/about/pac-20384919?p=1
https://my.clevelandclinic.org/health/diagnostics/4053-complete-blood-count
https://medlineplus.gov/lab-tests/complete-blood-count-cbc/
https://www.cc.nih.gov/ccc/patient_education/pepubs/cbc.pdf