Urobilinogen refers to the destruction of senescent red blood cells in the liver or spleen, and the hemoglobin in the red blood cells becomes indirect bilirubin, which enters the intestines with bile excretion and is metabolized into urobilinogen by bacterial decomposition in the intestines. Most of the urobilinogen will be excreted with the stool, but some of it will be absorbed by the intestinal wall and return to the liver, and then enter the kidneys or the bloodstream from the liver, and be excreted with the urine, and it will become urobilin after coming into contact with the air. Clinical urine routine test contains urobilinogen, if urobilinogen is positive, it means that there may be hepatocellular jaundice or hemolytic disease. Urobilinogennormal indicates that urobilinogen is normal, and it is also normal that urobilinogen is not detected in the urine routine. Causes of increased urobilinogen include liver cell damage, liver dysfunction, resulting in destruction of red blood cells in the liver; hemolytic jaundice resulting in destruction of red blood cells; cardiac insufficiency, constipation, hyperthermia and other causes; portal cirrhosis, congestive heart failure and sepsis. Due to liver dysfunction, the normal amount of urobilinogen absorbed from the intestine cannot be utilized and re-excreted through the biliary tract.