Complete Blood Count (CBC): What This Test Is and What Your Results Mean

A complete blood count, or CBC, is one of the most common blood tests. It measures the different cells in your blood, including red blood cells, white blood cells, and platelets. Your doctor may order it as part of a routine checkup or to help investigate symptoms such as fatigue, fever, weakness, or unusual bruising.

The acylcarnitine test measures the presence and levels of acylcarnitines in your blood. Acylcarnitines are substances produced when the body breaks down fatty acids for energy. This test helps detect metabolic disorders where the body cannot properly process fats, leading to a buildup of certain acylcarnitines in the blood.

The test is performed by drawing a small sample of blood, usually from a vein in your arm. A healthcare professional will clean the skin, wrap a band around your upper arm, and collect the blood into a small tube. The sample is then sent to a laboratory for analysis, and the entire process usually takes only a few minutes.

A healthcare professional will draw a small blood sample from a vein in your arm or, for newborns, from a heel stick. The blood is collected on a special filter paper and sent to a laboratory for analysis. No special preparation is typically required, though your doctor may ask about recent meals or medications.

A CBC can help detect a wide range of conditions, including anemia, infections, leukemia and other blood disorders, clotting problems, and signs of inflammation or immune system issues. It is also used to monitor chronic conditions and to track how well treatments, such as chemotherapy, are affecting your blood cells.

The acylcarnitine test primarily screens for inherited metabolic disorders, including: medium-chain acyl-CoA dehydrogenase (MCAD) deficiency, carnitine palmitoyltransferase (CPT) deficiencies, and various organic acidemias. These conditions affect how the body converts fat into energy and can cause serious health problems if not treated early.

Your results show whether your blood cell levels fall within normal ranges. Low red blood cells may suggest anemia, while a high white blood cell count can point to infection or inflammation, and abnormal platelet levels may affect clotting. Your doctor will interpret these values along with your symptoms and medical history to decide whether further testing or treatment is needed.

Normal results mean no abnormal levels of acylcarnitines were detected. Abnormal results may indicate a metabolic disorder, but further testing is usually needed to confirm a specific diagnosis. Your healthcare provider will interpret the results in the context of your symptoms, medical history, and other test results.