Warm autoimmune hemolytic anemia is a condition where the immune system attacks and destroys red blood cells causing anemia. There are several synonyms for this medical condition, including idiopathic autoimmune hemolytic anemia, warm antibody autoimmune hemolytic anemia and warm AIHA. The term idiopathic implies that the cause of the anemia is unknown whereas the terms warm antibody and warm AIHA refer to the type of antibodies that are involved in the destruction of red blood cells. These synonymous terms are often used interchangeably in medical literature and diagnosis, and treatment options for all types of autoimmune hemolytic anemia are similar.