Bilirubin and biliverdin are both pigments produced during the breakdown of hemoglobin in the body, particularly in red blood cells. Here's what they are:
Bilirubin: Bilirubin is a yellow pigment that forms as a result of the breakdown of heme, a component of hemoglobin found in red blood cells. When red blood cells reach the end of their lifespan, they are broken down in the spleen, liver, and bone marrow, releasing heme. This heme is then converted into bilirubin in the liver. Bilirubin is eventually excreted from the body through bile, which gives feces its characteristic brown color.
Biliverdin: Biliverdin is an earlier stage in the breakdown of heme. When heme is broken down, it first forms biliverdin, which is green in color. Biliverdin is then quickly converted into bilirubin in the liver. While biliverdin is a green pigment, it is less commonly seen in the body than bilirubin because it is rapidly converted.
Both bilirubin and biliverdin are important components of the body's natural processes for recycling and excreting waste products from the breakdown of red blood cells. Elevated levels of bilirubin in the blood can lead to jaundice, a condition characterized by yellowing of the skin and eyes, and may be a sign of underlying health issues.