Obstructive jaundice (Ie; Post-hepatic jaundice) is caused from the hindrance of bile draining through the bile ducts (in the liver) and/or from draining from its site of storage (gallbladder) to the small intestine. Backing up bile in your liver (a pretty nasty chemical which degrades lipids) is a sure way to damage your liver. You liver (unlike the care the pancreas takes with protease) doesn't go to great lengths to protect itself from bile. So if you get it "just" laying around, it will start chewing up things which ought not to be chewed up.
Pre-hepatic jaundices are caused by breaking down your RBCs prematurely (such as with hemolytic anemias) and the excess rush of RBC degradation products can damage the liver as well.
Hope that helps
