What is a Complete Blood Count?

A complete blood count (CBC) test is an affordable and efficient way of screening for, diagnosing, and monitoring conditions such as anemia and blood disorders. The test measures your red blood cells, white blood cells, and platelets within your body.

A comprehensive blood count (CBC) includes other tests as well, such as differential counting of white blood cells and immature red blood cells; mean platelet volume (MPV); which measures average platelet sizes.

What is a CBC?

A complete blood count (CBC) analyzes a sample of your blood to provide essential insight into its overall health, such as how strong or fragile your immune system is. A CBC can also assist providers with diagnosing diseases or overseeing treatments or medications more closely.

A complete blood count (CBC) measures your red blood cells, white blood cells and platelets in your blood. Additionally, this test provides information on the type and quantity of hemoglobin (a substance which carries oxygen through the blood) present.

Your healthcare provider may order a complete blood count (CBC) as part of your annual health checkup or to investigate unexplained symptoms such as fever, weight loss, night sweats, fatigue, bruising and bleeding. A CBC can also be useful in diagnosing conditions affecting blood cell counts such as anemia.

Your white blood cell count, or leukocyte count, measures the total number of immune system cells present in the blood. These immune system cells help fight infections and help your body heal itself; when numbers dip low enough they may indicate medical problems like bone marrow disorders, autoimmune disorders and cancer.

A complete blood count (CBC) may also include a differential, which means the lab will count all types of white blood cells and immature (also called blast) blood cells to provide more insight into your immune system and its functioning. This provides your provider with additional data regarding its health status.

Why do I need a CBC?

A complete blood count (CBC) test can assist your physician in assessing overall health and identify conditions such as anemia or infections. Furthermore, it can show if your platelet count is too low or too high – which could result in bleeding complications.

Platelets (leukocytes in a complete blood count or CBC) are blood cells responsible for creating clots to control bleeding in the body. When their count falls below normal (thrombocytopenia) or rises above it (thrombocytosis), this condition is called thrombocytopenia or thrombocytosis respectively. Platelet counts may also be affected by various things including autoimmune diseases and certain medications.

White blood cell (WBC) counts can also be altered by infection or inflammation, so having your WBC count checked with differential can provide insight into all the various kinds of white blood cells present.

A complete blood count (CBC) with hemoglobin can provide your physician with insight into your iron levels. Hemoglobin is a protein which transports oxygen through the blood.

For this test, a health care professional will collect a small sample of blood from one or more veins in your arm. A band may be placed around it to facilitate getting an adequate sample; then needle will be inserted into vein and taken as blood into test tube (you may feel slight pinch when needle goes in/out).

What happens during a CBC?

A complete blood count (CBC) measures the percentage of red, white and platelet cells found in your sample as well as measuring hemoglobin (which carries oxygen) and hematocrit (the proportion of your blood made up by red blood cells).

An advanced computer analyzes your blood sample to collect data. It can distinguish among various white blood cell types and measures platelet sizes to provide information to your physician about what may be occurring within your body, such as whether low levels of red blood cells indicate anemia or whether platelets are clotting normally. This test gives your physician insights into any changes within you body such as whether there are low red blood cell counts and/or platelets aren’t clotting correctly.

Your health care provider will collect a sample of blood from either an arm vein or, for infants and young children, from their heel. You may experience a slight pinching or pricking sensation as they sterilize the area before inserting a needle into a blood vessel to collect samples into tubes that will later be sent off for analysis in labs.

Your healthcare provider will follow up on your results depending on them, with further tests or referral to a specialist in blood disorders called a hematologist as needed. Additionally, if taking medications that affect cell counts such as chemotherapy drugs or diuretics, repeat CBC tests at regular intervals in order to monitor how effectively those medicines are working for you.

What are the results of a CBC?

A complete blood count (CBC) test provides doctors with clues for diagnosing diseases and health conditions through measuring the components of blood. A CBC can reveal conditions like anemia, cancer and vitamin and mineral deficiencies; however, further testing will often be needed in order to make an accurate diagnosis.

Doctors typically order CBCs as part of routine checkups or when suspecting health conditions. A CBC also helps monitor how effective treatment plans and medications that alter blood cell counts such as chemotherapy or radiation therapy are performing.

Phlebotomists will collect blood samples for your CBC test from veins on either the inside of your elbow or on the back of your hand; there should be no need to fast beforehand unless otherwise instructed by your provider.

CBC results will provide multiple measurements, including counting red blood cells, white blood cells and platelets; measuring hemoglobin concentration; and the number of reticulocytes (young red blood cells). When these levels drop significantly they could indicate anemia.

White blood cell counts that are elevated can indicate infection; conversely, low platelet counts increase risk for blood clotting issues due to specific medical conditions.