NHA Phlebotomy Certification Practice Exam

Which laboratory test would require a fasting sample for accurate results?

1. Complete blood count

2. Serum glucose test

3. Throat culture

4. Lipid panel

The correct answer is: Serum glucose test

A serum glucose test requires a fasting sample to ensure accurate results because fasting helps eliminate fluctuations in blood sugar levels that can occur after eating. When a person fasts for at least 8 hours prior to the test, it allows for a baseline measurement of glucose levels, providing a clearer assessment of how well the body manages blood sugar. This is crucial for diagnosing conditions such as diabetes or pre-diabetes. In contrast, a complete blood count does not necessitate fasting, as its results are not significantly impacted by food intake. A throat culture is also unaffected by fasting since it primarily detects infections and is based on a sampling from the oropharyngeal area. While a lipid panel may also require fasting for the most accurate lipid measurements, particularly triglycerides, the serum glucose test is more universally required to be done after fasting to obtain reliable data regarding glucose metabolism.