Common blood disorders: a primary care approach.

Many anemias and diseases of the blood-forming elements increase in incidence with advancing age. Iron deficiency remains the cause of most cases of anemia and may be related to inapparent blood loss. Other responsive anemias that can be managed by the primary care physician include vitamin B12 and folate deficiencies and drug- or autoimmune-related hemolytic anemia. Nonresponsive anemias, including hematologic malignancies, are quite common in older patients and require referral to a specialist. Platelet disorders are often produced by certain drugs and, like most refractory anemias, often require a bone marrow aspirate for diagnosis.