Usually jaundice (icterus) indicates that there is too much bilirubin in the body. During jaundice, the total amount of bilirubin levels in the blood is increased (hyperbilirubinemia). To define the term, bilirubin is a pigment derived from the metabolism of hemoglobin taken from old and damaged erythrocytes. In this process, old and damaged erythrocytes are first captured by the cells of the reticular-endothelial system (RES). Then, the erythrocytes are placed in few organs like spleen, liver, bone marrow, lymph nodes etc. The hemoglobin (or more precisely the part called the "hem") transforms into indirect (non-conjugated) bilirubin in the RES. In cases of excessive destruction of erythrocytes (hemolytic anemia), the level of indirect bilirubin increases (hemolytic icterus).


Indirect bilirubin is transported to the liver where the liver cells (hepatocytes) transform the indirect bilirubin into direct bilirubin(conjugated) in a process known as "conjugation". Direct bilirubin is then excreted through the bile in to the intestines. Bilirubin in the intestines transforms into sterkobilin, a product that gives the stool its color. Another part of the intestinal bilirubin transforms into urobilinogen which is reabsorbed by the blood circulation and transported back to the liver. In the liver, urobilinogen transforms into direct bilirubin and is excreted through the bile again. This is called "enterohepatic circulation". Another part of the urobilinogen is excreted trough the kidneys into the urine. In cases of billiary obstruction (by tumor or stone), direct bilirubin can’t be excreted into the intestines (white stools) and instead, it enters the bloodstream. High levels of direct bilirubin in the blood manifests with so called obstructive icterus. In this case, direct bilirubin is also found in the urine because this type of bilirubin can pass through the kidneys. That’s why the urine has a dark color (bilirubinuria).


If the liver is damaged (hepatitis, cirrhosis), blood levels of both types of bilirubin (direct and indirect) will be elevated because indirect bilirubin cannot be transformed into direct bilirubin nor can direct bilirubin be excreted into intestines. This type of icterus is called "hepatocelular icterus". Elevated levels of enzymes are also found in the blood which are derived from the damaged liver cells (AST, ALT, alcal phosphatasa and gama-GT). If liver damage is caused by hepatitis-B, then HBs-Ag, HBV-DNA and HBe-Ag will be also elevated.


In your case, it is possible to confirm that you are carrier of the hepatitis-B virus (HBV) because you have positive result for HBs-Ag. Negative results for HBV-DNA and HBc-Ag exclude chronic infection with HBV. Normal liver functional tests exclude the liver damage as reason for the jaundice. You can examine the blood levels of both types of bilirubin to confirm jaundice. Blood count with sedimentation, urine analyses and abdominal ultrasound scan are also necessary to explain the jaundice.