Aplastic anemia is a rare condition in which the bone marrow is unable to produce blood cells normally. The production of just some blood cells (such as red blood cells only) may be affected, or the production of all types of blood cells may be decreased.

Symptoms of aplastic anemia include:

• Fatigue, weakness, or lack of energy.
• Headaches or breathing problems that occur after exercise.
• Infections that keep returning or are more severe than usual.
• Frequent nosebleeds or bleeding under the skin.

Causes of aplastic anemia can include:

• Exposure to poisonous (toxic) chemicals.
• Certain medicines, such as medicines taken to treat cancer.
• Radiation treatments that destroy the bone marrow.
• Certain viral infections.

Aplastic anemia sometimes develops for no known reason.

In some cases, a person may need blood transfusions until his or her bone marrow is able to produce blood cells. In other cases, a person may need a bone marrow transplant.