KELVIN LEE

To better understand how jaundice occurs, we must know the anatomy and physiology of red blood cells. Red blood cells carry oxygen to all body parts. To perform this function, it needs a pigment called haemoglobin. This haemoglobin carries the oxygen. In simple terms, red blood cells contains haemoglobin and this haemoglobin carries oxygen. The normal life span of red blood cells is 120 days. So after 120 days, the red blood cells die off by a process called Haemolysis. New ones are formed through erythropoiesis in the bone marrow.
After 120 days the red blood cells are destroyed by the spleen. The red blood cells are broken down into haeme and globin. The globin is a protein and the haeme is divided into iron and unconjugated or insoluble bilirubin. Bilirubin is a yellow substance that the body makes during the normal breakdown of red blood cells. However, when there is disease or condition that affects the organs that excrete bilirubin or the excretion of bilirubin, it accumulates in the body. It becomes excess in the blood and deposited in the sclera of the eyes, skin and mucous membrane termed as Jaundice.
Therefore, Jaundice is defined as the yellowish discolouration of the eyes, the mucous membrane and the skin. Hence, is a neonate or a baby from the first day of life to 28 days develops jaundice within that period we term it as neonatal jaundice.


THE NORMAL EXCRETION OF BILIRUBIN
The insoluble bilirubin must be converted into soluble bilirubin before it is excreted through the faeces and urine. The insoluble bilirubin goes to the liver where the enzyme glucuroynl transferase binds the unconjugated bilirubin to glucuronic acid to make it soluble. The soluble bilirubin is transported to the gall bladder to form part of the bile. From the gall bladder, the soluble bilirubin goes into the small intestines. Some of the bilirubin is converted to stercobilin which gives the feaces it’s golden-brown colour. Some into urobilinogen which gives urine it’s amber colour. Hence, if there is a blockage and the bilirubin is not able to get to the small intestines for the conversion, hence the stool of a patient with jaundice is clay coloured and the urine is dark or “coca~cola ” colour .

CAUSES OF JAUNDICE
From the above information we have learnt that after the insoluble bilirubin is turned into soluble bilirubin it goes to the gall bladder to form part of the bile and then later to the small intestines.

This implies that if there is formation of gall bladder stones( which is called cholelithiasis) that’s blocks the emptying of the gall bladder into the small intestines, the bilirubin will accumulate in the gall bladder and sip through the walls of the gall bladder into the bloodstream and lead to Jaundice presentation.
Also if a patient has cholecystitis ( inflammation of the gall bladder), it makes it difficult for the transport of bilirubin from the gallbladder into the small intestines and it also leads to jaundice presentation.