How can a failure to fast before a blood test affect the sample?

When a patient fails to fast before a blood test, the composition of the blood sample can change significantly. One of the most notable effects is an increase in turbidity, which refers to the cloudiness or haziness of the plasma in the blood sample. This turbidity can be caused by various factors, including the presence of lipids from food intake, which may lead to a condition called lipemia.

When a person consumes food, particularly high-fat meals, fatty substances enter the bloodstream. These lipids can make the blood appear milky or cloudy, interfering with the analysis of certain components in the blood. Increased turbidity can compromise the accuracy of laboratory tests that are reliant on clear samples, influencing results such as cholesterol levels, triglycerides, and other lipid tests.

In summary, not fasting before a blood test can lead to an increase in turbidity due to the presence of lipids, which impacts the quality and reliability of the blood sample for testing.