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Full blood count

Full blood count

Full blood count
Full blood count

In the investigation of blood diseases, the simplest test is a full blood count (FBC). A full blood count measures the following in a sample of blood:

•    the amount of haemoglobin

•    the number of the different cells – red blood cells (erythrocytes), white blood cells (leucocytes) and platelets (thrombocytes)

•    the volume of the cells

•    the erythrocyte sedimentation rate (ESR) – a measurement of how quickly red blood cells fall to the bottom of a sample of blood.



Anaemia is one of the commonest diseases of the blood. It may be due to:

•    bleeding – loss of blood

•    excessive destruction of red cells

•    low production, for example because the diet is lacking, or deficient in, iron (Fe).

  A medical student has examined an elderly patient with a very low level of haemoglobin and is discussing the case with her professor:

Professor:  What’s the most likely diagnosis in this case?

Student:  Most probably carcinoma of the bowel with chronic blood loss. What’s

Professor: against that as a diagnosis?

Student:  Well, he hasn’t had any change in his bowel habit, or lost weight.

Professor:  What else would you include in the differential diagnosis of severe anaemia in a man of this age?

Student: He might have leukaemia of some sort, or aplastic anaemia, but that’s rare – it would be very unusual. Another cause is iron deficiency, but he seems to have an adequate diet.

Professor: OK. Now, there’s another cause of anaemia which I think is more likely.

Student: Chronic bleeding ulcer?

Professor: Yes, that’s right. But what about pernicious anaemia? Can you exclude that?

Student: Well, he’s got none of the typical neurological symptoms, like paraesthesiae.

Pernicious anaemia

Jordi Pons, the medical student from Barcelona, has made some language notes in his textbook.

icious anaemia (PA) is a condition in which there  phy of the gastric mucosa with consequent failure of i intrinsic factor production and vitamin 812 malabsorption. 1 The onset is insidious, with progressively increasing ‘ symptoms of anaemia.

Complete blood count

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