This page explains the Complete Blood Count (CBC) test, how it is done, and what your results may indicate.

This test measures several parts of your blood, including red blood cells, white blood cells, and platelets. It helps doctors evaluate your overall health and detect a wide range of disorders, such as anemia, infection, and certain diseases. The CBC provides important information about the number, size, and maturity of different blood cells in your sample, giving a snapshot of how well your body is producing and maintaining these vital components.

A creatinine test measures the amount of creatinine in your body fluid, typically in blood (serum). Creatinine is a waste product produced by normal muscle metabolism and is normally filtered out of the blood by your kidneys. When your kidneys are functioning properly, they remove creatinine from your blood and excrete it in urine.

For this test, a healthcare professional will draw a small sample of blood from a vein in your arm, usually at the inner elbow. They will first clean the area with an antiseptic wipe and tie a tourniquet above the site to make the vein more visible. Then, they will insert a thin needle into the vein and collect blood into a vial or tube. You might feel a quick sting or pinch, but the entire process takes only a few minutes. After the needle is removed, you'll be asked to apply firm pressure with a cotton ball to stop any bleeding, and a small bandage will be placed over the site.

A healthcare provider will draw a blood sample from a vein in your arm. The sample is then sent to a laboratory for analysis. The procedure is quick and usually takes only a few minutes. You may be asked to fast for 8-12 hours before the test, depending on your doctor's instructions.

Your results will show levels for each blood component, and your doctor will explain what they mean based on your age, gender, and medical history. Generally, low red blood cell counts may suggest anemia or blood loss, while high counts can indicate dehydration or other conditions. White blood cell counts outside the normal range often signal infection or inflammation. Platelet counts affect clotting, so low levels may raise bleeding risk, whereas high levels can increase clotting risk. However, these are just general guidelines—many factors can influence results, so your doctor will interpret them in context.

Normal creatinine levels vary based on age, sex, and muscle mass. Generally, higher than normal creatinine levels may indicate that your kidneys are not filtering waste effectively. Lower than normal levels are less common but may occur in conditions involving reduced muscle mass. Your doctor will interpret your results in the context of your overall health and other test results.