2. ANAEMIAS
• Anaemia is defined as a decrease in haemoglobin level (or total circulating red cell mass)
for the age and sex of a person.
• The haemoglobin level in adult females is lower as compared to adult males of the same age
group. This is because of the influence of menstrual loss and lack of androgens.
• Haemoglobin (Hb) is contained in RBCs, which circulate in blood. These are biconcave discs,
6.7- 7.7 (mean 7.2) μm in diameter.
• Their number in circulation of an adult male normally is 4.5-5.5 (mean 5.0) X1012/L. Each
RBC has a volume of 92 fl and contains 29.5 pg of Hb, the concentration of which in an
individual RBC is 33 g/dl. Normal life span of a RBC, in peripheral blood is about 120 days
3. CLASSIFICATION AND AETIOLOGY
There are various criteria for classification of anaemia. Each type of
classification has certain advantages and disadvantages. For routine
laboratory work, the morphological classification is most useful.
• In this classification anaemias are divided into three main groups
depending upon
• the size of RBC and amount of haemoglobin present in each cell.
• These groups can be
• identified by measuring absolute values
• as well as by examination of red cell morphology on stainedblood
film.
4. CLASSIFICATION OF ANEMIAS:
These groups are:
Microcytic Hypochromic Anaemia: In this type of anaemia individual RBCs are smaller in
size than normal and contain subnormal amount of haemoglobin. All absolute values
(MCV, MCH, and MCHC) are below normal.
This type of anaemia is commonly seen in:
• Iron deficiency
• Thalassaemia
• Sideroblastic anaemia
• Anaemia of chronic disorders (some
cases)
5. CLASSIFICATION OF ANEMIAS:
Macrocytic Anaemia: In this type of anaemia individual RBCs are larger than normal, the amount of
haemoglobin in each cell is usually below normal. Absolute values show increased MCV with usually
normal MCH/MCHC. This type of anaemia is commonly seen in:
• Megaloblastic anaemia
• Aplastic anaemia
• Haemolytic anaemia
• Liver disease
• Myxoedema
• Hypopituitarism
• Pregnancy
• Alcoholism
6. CLASSIFICATION OF ANEMIAS:
Normocytic Normochromic Anaemia:
In this type of anaemia, although the haemoglobin concentration in
blood is reduced the individual RBCs appear normal and absolute
values are also within normal limits. This type of anaemia is seen in:
• Acute blood loss
• Leukaemia
• Bone marrow infiltration
• Chronic renal failure
• Chronic infections (Chronic disorders
7. DIAGNOSIS
Following investigations are to be performed for diagnosing a case of anaemia:
• Estimation of Haemoglobin (Hb).
• Estimation of Total Red Blood Cell Count (TRBC).
• Estimation of Haematocrit (Hct) or Packed Cell Volume (PCV).
• Calculation of absolute values.
• Examination of peripheral blood film.
• Reticulocyte count
• After determining the morphological type of anaemia, the patient is further
investigated to determine the cause of it
