A bleeding belly button is not a sign of an umbilical hernia, according to Mayo Clinic. Most commonly, an umbilical hernia causes swelling. A bleeding belly button is a sign of portal hypertension, which can cause bleeding varices, a potentially life-threatening condition, explains WebMD.
Portal hypertension occurs when the veins in the liver become blocked, states WebMD. The veins coming from the stomach, spleen, pancreas and intestine join the portal vein and branch off through the liver. When the liver is damaged, this can cause a blockage, and the veins begin to swell. The swollen veins may be in the stomach, rectum, esophagus or belly button area. When rupture of the veins occurs, immediate medical help should be sought.