Understanding your laboratory tests

What do they mean, and are they necessary?

- DR. EDSEL MAURICE T. SALVANA

For many Filipinos, a doctor's visit isn't complete without two components: a laboratory request and some sort of medicine.

While some patients do need both, there are many instances when neither testing nor treatment is needed. For those coming in for their annual checkup, or what some refer to as a wellness visit, the laboratory test becomes an object of intense focus, and in some cases, anxiety. What do these tests really mean, and should you be getting them at all?

Children need to be seen by pediatricians regularly to ensure that they are growing and gaining weight at a normal rate. They also get their scheduled vaccinations regularly. After they "graduate" from their pediatrician, however, the regular checkups fall off except for required college or employment examinations. Most workplaces ask for a chest X-ray every one to two years because there is so much tuberculosis in the Philippines. Pre-employment tests can be quite extensive, including hepatitis B screening, a complete blood count, liver and kidney tests, and urinalysis. Assuming a person is asymptomatic, has no risk factors, and lives a healthy lifestyle, routine laboratory tests aren't necessary until around 35 years of age. At that point, fasting glucose and lipid panel tests are recommended. Doctors go over these tests and use them to detect any potential problems that need further workup. In my experience, patients will stare at the printouts with fascination and will even share them with relatives, especially if they are doctors like me. To help people understand, I will try to explain what these tests are, what they might mean, and why we do them.

Complete blood count (CBC)