Bloods
Red Blood Cells
What makes up the Red Blood Cell Count?
Haemoglobin (Hb)
o Looks at the concentration of Hb within the blood. Hb is the
protein that carries oxygen in blood and is the most important
value to look at.
MCV
o Mean volume of red blood cells. Main method used to classify
anaemia.
Reticulocyte Count
o Measures the production of red cells by looking at the
concentration of immature blood cells. Increased in blood
loss and haemolytic anaemia because the bone marrow
is working hard to replace the lost cells.
Red Cell Count
o Concentration of red blood cells within the blood
Haematocrit/ packed cell volume (PCV)
o Volume percentage of red blood cells in the blood
MCH
o Mean Hb quantity within blood cells (affects the colour of cells
“-chromic”)
Most normocytic and macrocytic anaemias are
normochromic
Most microcytic anaemias are hypochromic
(except for anaemia of chronic disease)
Red Blood Cell Distribution Width (RCW)
o Measure of the variation of red blood cell volumes. Used with
MCV to determine whether anaemia is due to a mixed or
single cause. Raised RDW = anisocytosis.
Anaemia
A reduced concentration of haemoglobin within the blood.
What other tests should be done?
- WCC and platelet count – if both abnormal, a bone marrow
cause is likely.
- Reticulocyte Count- If raised, the cause is blood loss or
haemolytic anaemia.
- MCV:
, Causes of Anaemia by MCV
Microcytic Normocytic Macrocytic
(decreased volume of (normal volume of red (increased volume of
red blood cells) blood cells) red blood cells)
Sideroblastic Acute Blood Loss Megaloblastic
Decreased B12
Iron Deficiency Haemolytic Anaemia
Decreased Folate
Thalassaemia Sickle Cell
Non-Megaloblastic
Chronic Disease Alcohol
Reticulocyte
Liver Disease
Pregnancy
Hyperthyroidism
Bone Marrow Failure (aplastic anaemia,
myelodysplasia, leukaemia, myelofibrosis)
Tests for specific causes:
- Haematics
o B12 and folate, ferritin
- Iron Studies
o Iron, transferrin, total iron binding capacity, ferritin
- TFTs
- Blood Film and Bone Marrow Biopsy (if bone marrow
cause/haemolytic anaemia/sideroblastic anaemia suspected)
- Hb Electrophoresis (If thalassaemia/sickle cell suspected)
- Bilirubin (Raised in Haemolysis)
Red Blood Cell Disorders
Iron Deficiency Anaemia
A lack of iron intake or excessive iron requirements resulting in a Hb
<130g/L (male) or Hb <120g/L (women)
Red Blood Cells
What makes up the Red Blood Cell Count?
Haemoglobin (Hb)
o Looks at the concentration of Hb within the blood. Hb is the
protein that carries oxygen in blood and is the most important
value to look at.
MCV
o Mean volume of red blood cells. Main method used to classify
anaemia.
Reticulocyte Count
o Measures the production of red cells by looking at the
concentration of immature blood cells. Increased in blood
loss and haemolytic anaemia because the bone marrow
is working hard to replace the lost cells.
Red Cell Count
o Concentration of red blood cells within the blood
Haematocrit/ packed cell volume (PCV)
o Volume percentage of red blood cells in the blood
MCH
o Mean Hb quantity within blood cells (affects the colour of cells
“-chromic”)
Most normocytic and macrocytic anaemias are
normochromic
Most microcytic anaemias are hypochromic
(except for anaemia of chronic disease)
Red Blood Cell Distribution Width (RCW)
o Measure of the variation of red blood cell volumes. Used with
MCV to determine whether anaemia is due to a mixed or
single cause. Raised RDW = anisocytosis.
Anaemia
A reduced concentration of haemoglobin within the blood.
What other tests should be done?
- WCC and platelet count – if both abnormal, a bone marrow
cause is likely.
- Reticulocyte Count- If raised, the cause is blood loss or
haemolytic anaemia.
- MCV:
, Causes of Anaemia by MCV
Microcytic Normocytic Macrocytic
(decreased volume of (normal volume of red (increased volume of
red blood cells) blood cells) red blood cells)
Sideroblastic Acute Blood Loss Megaloblastic
Decreased B12
Iron Deficiency Haemolytic Anaemia
Decreased Folate
Thalassaemia Sickle Cell
Non-Megaloblastic
Chronic Disease Alcohol
Reticulocyte
Liver Disease
Pregnancy
Hyperthyroidism
Bone Marrow Failure (aplastic anaemia,
myelodysplasia, leukaemia, myelofibrosis)
Tests for specific causes:
- Haematics
o B12 and folate, ferritin
- Iron Studies
o Iron, transferrin, total iron binding capacity, ferritin
- TFTs
- Blood Film and Bone Marrow Biopsy (if bone marrow
cause/haemolytic anaemia/sideroblastic anaemia suspected)
- Hb Electrophoresis (If thalassaemia/sickle cell suspected)
- Bilirubin (Raised in Haemolysis)
Red Blood Cell Disorders
Iron Deficiency Anaemia
A lack of iron intake or excessive iron requirements resulting in a Hb
<130g/L (male) or Hb <120g/L (women)
