True anemia: incidence and significance in the elderly.

The incidence of anemia increases as humans age, but in healthy aging individuals followed longitudinally, significant anemia does not develop in the absence of disease. Mild lymphopenia, as well as abnormal platelet function tests and increased coagulability when measured in vitro, also tend to develop in aging individuals. Hematologic neoplasia in the elderly behaves very similarly to the way it does in young individuals, but elderly individuals with hematologic neoplasms have a poor response to therapy.