In aplastic anemia, the bone marrow does not produce new cells leaving the body susceptible to organ failure, bleeding, and infection. Recently, researchers have discovered that most cases of severe aplastic anemia are autoimmune disorders in which the body's own immune system attacks tissues and organs. They believe that autoreactive or abnormal immune cells known as lymphocytes suppress blood cell production and division. A number of environmental factors, including drugs, benzene exposure, insecticides, and viruses have been identified as causes for the immune attack that leads to aplastic anemia. However, in the majority of cases, there is no identifiable cause.
Myelodysplastic syndrome is a related disease that is actually a cancer of the blood cells.
Click here to find out more information on aplastic anemia. It is characterized by destruction of red blood cells, the development of blood clots, impaired bone marrow function, and an increased risk of leukemia. It is most common in people age 35-40 and is closely related to aplastic anemia. PNH has a wide spectrum of symptoms and can therefore be difficult to diagnose. Some of the more common symptoms include severe abdominal pain crises, severe headaches, back pain, excessive weakness, fatigue, recurrent infections, and sometimes bright red blood or dark, tea-color urine.