Glossary
A Complete Blood Count (CBC) is a comprehensive blood test that provides detailed information about the cells in a patient's blood. This test is often used as a broad screening tool to evaluate a person's general health status, but it can also be used to diagnose or monitor a variety of diseases. The CBC measures several components and features of the blood, including red blood cells (RBCs), white blood cells (WBCs), and platelets. These three types of cells perform different functions in the body, and abnormalities in any of them can indicate a variety of medical conditions.
Red blood cells, also known as erythrocytes, are responsible for carrying oxygen from the lungs to the rest of the body. They contain a protein called hemoglobin, which binds to oxygen and gives the cells their red color. The CBC measures the total number of red blood cells in the blood, the amount of hemoglobin, and the portion of the blood volume made up by the red blood cells (hematocrit). It also measures the size, shape, and physical characteristics of the red blood cells, which can help diagnose certain types of anemia and other disorders. White blood cells, or leukocytes, are part of the body's immune system and help fight infections. They are produced in the bone marrow and are released into the bloodstream in response to signals from the body that an infection is present. The CBC measures the total number of white blood cells and also breaks down the count into the five different types of white blood cells: neutrophils, lymphocytes, monocytes, eosinophils, and basophils. Each of these types of cells plays a different role in the immune response, and changes in their numbers can indicate different types of infections, immune disorders, or other medical conditions. Platelets, or thrombocytes, are small cell fragments that play a crucial role in blood clotting. When a blood vessel is damaged, platelets clump together to form a plug that helps stop the bleeding.
The CBC measures the total number of platelets in the blood and can also provide information about their size and the range of sizes in the sample. Abnormal platelet counts can indicate a bleeding disorder, a bone marrow disease, or other medical conditions. In addition to these measurements, the CBC also includes a differential (or diff), which is a detailed breakdown of the different types of cells in the blood. This information can help diagnose specific types of anemia, infections, immune disorders, and blood cancers. The CBC is a routine test that is often part of a regular health check-up. However, it can also be ordered by a doctor if a patient is experiencing symptoms such as fatigue, weakness, fever, bruising, or bleeding, which could indicate a problem with the blood cells. The test is performed by drawing a small amount of blood from a vein, usually in the arm. The blood is then sent to a lab, where it is analyzed using a machine that can count the cells and measure their characteristics. The results of the CBC can provide a lot of information about a person's health, but they need to be interpreted in the context of the patient's symptoms, medical history, and other test results. Abnormal results can indicate a wide range of conditions, from minor infections to serious diseases, so it's important to discuss the results with a healthcare provider to understand what they mean.
In conclusion, the Complete Blood Count is a vital diagnostic tool that provides a wealth of information about the cells in the blood. By measuring the number, size, and characteristics of the red blood cells, white blood cells, and platelets, it can help diagnose a wide range of medical conditions and monitor the body's response to treatment.