Barbara J. Bain

Chapter 23 – Approach to the diagnosis and classification of blood diseases

An abnormal blood count or blood cell morphology does not necessarily indicate a primary haematology problem because it may reflect an underlying nonhaematological condition or may be the result of therapeutic interventions. Anaemia occurs in many conditions, but a primary blood disease should be considered when a patient has splenomegaly; lymphadenopathy; a bleeding tendency or thrombosis; and/or non-specific symptoms (malaise, sweats, or weight loss). As with any clinical problem, the first steps in determining the diagnosis include obtaining a careful clinical and drug history and thorough physical examination. The result of these, in combination with the patient’s age, sex, ethnic origin, social and family history, and knowledge of the locally prevalent diseases, will determine subsequent laboratory investigations.