What is pancytopenia? Pancytopenia is a deficiency of all types of blood cells, including white blood cells, red blood cells, and platelets. It occurs when your body cannot produce enough blood cells because the bone marrow stem cells that form blood cells do not function normally. Pancytopenia has widespread effects on the entire body by leading to oxygen shortage as well as problems with immune function. Aplastic anemia is a medical term that refers to a decrease in production of all types of blood cells. Pancytopenia occurs in two forms: idiopathic, in which the cause is not known, but is often autoimmune, meaning that the body attacks its own tissues as foreign substances; and secondary, often caused by environmental factors. Approximately half of all pancytopenia cases are idiopathic. In other cases, viral infections, radiation or chemotherapy treatments, drug reactions, and exposure to toxins may precipitate the development of pancytopenia. Pancytopenia may develop slowly over time or suddenly, and it can progress in a variety of ways. Symptoms of pancytopenia can include bleeding, easy bruising, fatigue, shortness of breath, and weakness. The decrease in white blood cells, which are involved in the body’s defense, or immune, system, also leads to an increased risk of infection. Treatments for pancytopenia include drugs that suppress the immune system (immunosuppressant drugs) and bone marrow stimulant drugs, blood transfusion, bone marrow transplant, and stem cell replacement therapy. In some cases, symptoms of pancytopenia can be severe or life-threatening. Seek immediate medical care (call 911) if you experience high fever, seizures or convulsions, difficulty breathing, heavy bleeding, or confusion or loss of consciousness for even a brief moment.