A blood test is an important laboratory procedure that can determine a person’s physiological and biochemical condition. From the time a baby is born, this procedure may already be required by physicians.

Medical technologists perform this laboratory analysis on a blood sample. The blood is normally extracted from a person’s major vein situated just below the center of the right arm.

Specifically, a blood test will be able to determine if a person carries certain diseases and whether his internal organs are functioning well or not. It can also find out the mineral content in the body, the effectiveness of medicines and even whether a woman is pregnant.

Basically, there are three types of blood tests. These are the biochemical analysis, molecular profiles and cellular evaluation.

Biochemical analysis – This blood test measures the level of a person’s sodium, potassium, chloride, bicarbonate, magnesium, calcium, creatinine, glucose and blood urea nitrogen. Before having your blood sample taken at the laboratory, patients are usually asked to fast or not eat anything eight to 12 hours. This is a must for people wanting to check their blood sugar and cholesterol levels.

Through this test, physicians are then able to prescribe what types of food their patients need to avoid to maintain their health.

Molecular profiling – This type of test enables medical professionals to determine the molecular anatomy of body cells particularly in relation to diseases. This also helps them develop new diagnostic and therapeutic methods for clinical intervention. Specifically, this blood test looks into and classifies tissues to be able to provide an accurate diagnosis and prognosis on the patient’s condition.

Molecular profiles vary and these include protein electrophoresis, the western blot (detects the presence of antibodies specifically antibodies), liver function test (targets the blood levels in the liver), polymerase chain reaction (focuses on the DNA sequences), northern blot (focuses on RNA sequences) and sexually transmitted disease or STD.

Cellular evaluation – This test covers different types such as the full blood count, cross matching and blood cultures. The full blood count is a routine test required to find out a patient’s WBC count, RBC count, hematocrit, hemoglobin and red cell distribution (erythrocyte sedimentation rate). This is helpful in determining the stage of a person’s disease.

Cross matching is the process required before a blood transfusion procedure. It aims to test the blood compatibility of the donor and the potential recipient. This procedure can be done through the computer or serologically by a certified laboratory technician.

Blood cultures are meant to determine the presence of microorganisms including bacteria and fungi in the blood. The blood sample is incubated in a controlled environment and then observed for microorganisms. Up to three blood cultures need to be done to be able to confirm whether the result is positive or negative.

A simple blood test does not pose any danger or risk so this should not scare you if you’re being asked by your physician to take one. Slight complications may occur but these are only in rare cases. Possible complications include infection, bleeding, bruising, dizziness and hematoma.

Originally posted on November 27, 2010 @ 5:23 pm