What type of test can measure the concentration of glucose in a patient's blood?

The fasting blood sugar test is specifically designed to measure the concentration of glucose in a patient's blood. This test typically requires the patient to fast for a period before the sample is taken, ensuring that the measurement reflects their baseline glucose levels without the influence of recently ingested food. Elevated glucose levels can indicate conditions such as diabetes, making this test crucial for diagnosing and monitoring blood sugar levels.

The other tests listed serve different purposes: a complete blood count evaluates overall health, assessing components like red and white blood cells; a cholesterol profile focuses on lipid levels in the blood, which are important for assessing cardiovascular risk; and a liver function test measures enzymes and proteins associated with liver health. None of these tests measure glucose concentration directly, which distinguishes the fasting blood sugar test as the correct choice for this specific function.