Cirrhosis, suh ROH sihs, is a disease of the liver in which scar tissue forms throughout the organ. Groups of cells called regenerative nodules, surrounded by sheets of scar tissue, replace the normal spongy tissue of the liver. The diseased organ may be unable to perform such vital functions as manufacturing proteins and removing harmful substances from the blood. The affected tissue may block the flow of blood, causing high pressure in blood vessels that serve the liver. Internal bleeding may then result. The blockage also may lead to the accumulation of fluids in the abdomen.