The thalassemias are the commonest single gene disorders in the world population and there are few hospital laboratories which will not, at one time or another, have to deal with a blood sample from a patient suspected of having one of these conditions.
Clinical haematology is one of the few discliplines in which the specialist is able to closely integrate clinical and laboratory medicine within the one speciality.
The study of the blood has a long history. mankind probably always has been interested in the blood, since it is likely that even primitive man realized that loss of blood, if sufficiently great, was associated with death. in Biblical refences, "to shed blood" was a term used in the sense of "to kill".
The importance of clinical evaluation of patients with bleeding disorders should not be overemphasized or minimized.
The detection and diagnosis of anemia are frequently the focus of attention in the care of patients because accurate quantification is not difficult to achieve and rational analysis of the problem is possible. anemia is not a diagnosis in itself, but merely is an objective sign of the presence of disease.