Laboratory Test Index

Medical laboratory testing is an important part of medicine today. It plays a crucial role in the detection, diagnosis, and treatment of disease in patients. It is estimated that 60 to 70% of all decisions regarding a patient's diagnosis and treatment, hospital admission, and discharge are based on laboratory test results.

There are two common categories of medical tests. Screening tests are used to detect disease when there are little or no signs and symptoms of the disease present. Diagnostic tests are used when a disease is suspected, to confirm or rule out the diagnosis. In this index, these tests are organized into three tables: Blood Tests, Urine Tests, and Stool Tests.

Despite advancements in technology, it is extremely important to remember that no test is completely accurate. It is not uncommon to have results that are either false-positives or false-negatives. A false-positive result is one that is incorrectly abnormal in a person who does not have the disease. A false-negative result is one that is incorrectly normal in a person who has the disease. Therefore, it is extremely important to remember that we are treating a "person" and not a "lab value," and that decisions should always be made based on the totality of all data (i.e., symptoms, signs, tongue, pulse, and all others), and never just on lab test alone, especially in light of false-positive or false-negative results.

The reference range refers to a range of numbers that encompass 95% of healthy people in the population. Reference values should be used as guidelines only, as they vary due to many factors, such as demographics of the healthy population, specific methods and/or instruments used to measure the specimens, and variations among the laboratories. Therefore, the test results should be interpreted based on the reference range of the laboratory that actually performed the tests.