Why would bilirubin levels be increased in sickle cell anemia, but normal in acute blood loss?

Answer 1

I'm not sure. I think it is because acute blood loss is short term and sickle cell is a chronic issue involving misshapen cells. The sickled cells get stuck in odd places and cause all sorts of problems. This answer is an educated guess.

Answer 2

because sickled cells have a shortened life span. this causes what's called hemolysis, or the red blood cells to die. Red blood cells are red because they have bilirubin in them, so when they die, the bilirubin is released. People with sickle cell disease make more red blood cells to attempt to make up for this deficiency, but many of these new red blood cells are also sickled, so the process starts all over again leading to more bilirubin production.