When we are talking about blood test, it refers to a procedure wherein a blood sample is collected from a person's vein for laboratory examination. It is probably one of the most often guided medical tests. The objective of producing a blood test may differ from one individual to another. For a disorder free and healthy person, blood test is performed to identify the blood type, glucose and other blood elements. On the opposite, a person can require blood examination to define hemoglobin levels, cholesterol levels, or presence of pathogens in the blood sample. For this case, fasting before blood test is needed to get accurate results.
There are many types of blood lab tests, being up to the approach for which the examination has been performed. For instance, examination of the chemical constituents of blood is done to check the concentration of electrolytes (calcium, potassium, magnesium, sodium, chloride), creatine, glucose, and urea. The readings of the test are then collated with the reference ranges established for correct functioning of the body metabolism. For this case scenario, blood test is performed to evaluate the health status of a person.
It needs to be taken into consideration that not all lab blood tests require fasting before to the examination. Types of blood tests that call for fasting are lipid profile's tests, glucose, and lactose tolerance test.