The examination of a patient’s blood is extremely useful as an aid to diagnosis in medicine since many signs can be picked up from deviations from its normal composition about diseases and disorders of the body. Haematology is one of the health sciences that plays an extremely important part in medicine, and is concerned with the study of blood composition, both in health and disease, and of the blood forming marrow of the bones.
The study of haematology includes the understanding of the normal components of the blood, the serum, blood proteins and types of cells including red and white. The red cells are mainly concerned with the transport of oxygen around the body which is facilitated by the haemoglobin they contain, whilst the white blood cells are part of the body’s defenses against infection. Thus a raised white cell count in a sample of blood is an indication to a doctor that there is some kind of infection present even though it may not reveal the actual source of the infection.
There are other ways that the blood composition can change in regard to antibodies, volume, viscosity, and clotting ability, and more subtle variations in the chemistry of its constituents such as proteins and fats. Careful analysis of blood samples can help identify disease or chronic conditions such as high cholesterol which may predispose towards disease.
Some examples of problems that show up through blood analysis are anaemia, where oxygen transport around the body is inadequate, acute or chronic infections by viruses or bacteria, and certain cancers such as secondary cancers of body organs or primary cancers of the blood like leukaemia. Anaemias can occur from lack of adequate numbers of red blood cells, lack of adequate haemoglobin caused by inadequate amounts of important constituents like iron or vitamin B, or from abnormal haemoglobin molecules as in sickle cell anaemia. Bleeding problems can occur from lack of certain vital constituents called clotting factors and this may be a genetic trait that can be picked up from looking at the blood.
Haematologists work mainly in a laboratory, using microscopes, centrifuges and various kinds of specialist equipment, examining blood samples and helping to advise doctors regarding their patients’problems. It is important and quite specialized work that demands accuracy of measurements and attention to detail.
For a doctor, correct diagnosis is the first essential in treating a sick patient, and haematology is one of the important health sciences that helps considerably in this respect.