Analyzing Your Health with Standard Clinical Laboratory Tests

What do all these tests measure?
The Complete Blood Count (CBC) measures the levels, or counts, of the different types of cells in the blood. In particular, the CBC measures hemoglobin and hematocrit to detect the presence of anemia, red and white blood cell counts to detect the presence of infections, and a differential white blood cell count and red blood cell examination to assess cellular shape, size and distribution. The CBC requires drawing a small amount of blood from a subject.

Urinalysis requires collecting urine from a well-hydrated subject. Results from urinalysis can help detect diabetes, acid-base imbalances, fluid or electrolyte disturbances, and urinary tract infections. Kidney function is assessed through urinalysis.

Glucose is assessed from a blood sample. An elevated blood glucose level may indicate the presence of diabetes. A fasting blood glucose level is the most specific, but least sensitive, method for diagnosing diabetes mellitus. Further testing is required to diagnose diabetes. In the event that further testing is warranted, subjects are referred to their personal physicians.

The lipid profile is a test that requires the participant to be fasting for 10 to 12 hours. Total cholesterol and triglyceride levels are measured in this profile, as well as a breakdown of the high density lipoprotein (HDL, the "good" cholesterol) and low density lipoprotein (LDL the "bad" cholesterol). Much of the research conducted at RLI is concerned with lifestyle changes and the lipid profile is used frequently to assess the effectiveness of dietary and activity interventions.

Liver function and electrolyte balance also are assessed from a blood sample.

All results of blood and urine analysis are discussed with each study participant and subjects are given copies of their results to review with their own health care providers.

How should I prepare for laboratory tests?

For tests in which you need to fast, only water should be consumed during the 10 to 12 hours before the blood sample is drawn. The research staff at RLI encourages you to drink plenty of water as it ensures proper hydration and makes drawing blood easier. Also, you are permitted to take any prescription medications during this time period.