LFT (Liver Function Test)

The Bilirubin Total measures the amount of bilirubin present in the blood of a person. Bilirubin is an orange-yellow waste pigment produced by the normal breakdown of heme. The heme is a component of hemoglobin and is found in red blood cells. The liver processes the bilirubin and eliminates it from the body. 

The life span of red blood cells is about 120 days. The heme which is released from the hemoglobin is converted into bilirubin which is called unconjugated bilirubin. It is then carried to the liver by proteins, where it gets attached to sugars and becomes conjugated bilirubin. This conjugated bilirubin enters the bile from the liver and passes to the small intestine. Here, it gets broken down by the bacteria and further gets eliminated in the stool. These breakdown products of bilirubin are responsible for giving the characteristic brown color to the stool.

A healthy adult body produces approximately 250 - 350 mg of bilirubin daily. About 85% of bilirubin comes from damaged or degraded RBCs while the remaining amount comes from the bone marrow or liver.

Small amount of unconjugated bilirubin is released in the blood normally, but there is no virtual presence of conjugated bilirubin in the blood. 

Both the forms of bilirubin can be measured or evaluated by the laboratory tests, and total bilirubin (sum of conjugated or unconjugated bilirubin) may be reported. In case there is an increase in levels of bilirubin, there will be yellowing of the skin and white of the eyes, giving the appearance of jaundice.  

The Protein Total, Serum Test measures the total amount of the various types of proteins in the serum. Proteins are known as building blocks of all cells and tissues. They are very important for the growth and development of the body. The proteins are responsible for forming the structural part of most of the organs and help in making up of enzymes and hormones which regulate the functions of the body.

In the blood, two classes of proteins are found which include albumin and globulin. Around 60% of the total protein is formed of albumin which is produced by the liver. Albumin works as a carrier protein for various small ions and molecules. It also acts as a source of amino acids for tissue metabolism and as the principal component which is involved in the maintenance of osmotic pressure.

The rest of the proteins present in the plasma are globulins which include enzymes, antibodies, carrier proteins, hormones, and various other types of proteins. In the blood, the protein total serum levels are relatively stable, which means that there is a fine balance in the loss and production of the protein molecules.

If this delicate balance is disturbed due to any illness or disease then this test is done to analyze the reason for it.