There are many reasons why anemia is so common in HIV-infected people. HIV itself can cause anemia. In addition, antiretrovirals, chemotherapy, and many other drugs used to treat people with HIV can reduce the number of red blood cells in the body. For example, AZT is a major cause of anemia in people receiving this drug. I want to lay down right here because I just don't have the energy.
Severe anemia can be life-threatening.
But even mild to moderate anemia can rob a person of energy and make it hard to have a normal life. There are different ways of treating anemia. Severe anemia is usually treated with blood transfusion. Since transfusion always carries the potential risk of infection or reactions, patients generally are not transfused unless their anemia is serious. I probably had a good dozen and a half transfusions between 1990 and 1995.