Anaemia

Types of anaemia:

There are 3 major types, classified in terms of their mean cell volume (MCV):

• Hypochromic microcytic with a low MCV
• Normochromic normocytic with a normal MCV
• Macrocytic with a high MCV

Causes of microcytic anaemia:

• Iron deficiency (most common cause)
• Chronic disease
• Thalassaemia

Causes of normocytic anaemia:

• Chronic disease
• Hypo-endocrine disorders
• Aplastic anaemia
• Haemorrhage

Causes of macrocytic anaemia:

• Megaloblastic anaemia (vitamin B₁₂/folate deficiency)
• Alcoholism
• Liver disease
• Aplastic anaemia

Symptoms:

• Asymptomatic
• Fatigue
• Headaches
• Faintness
• Breathlessness
• Angina of effort
• Intermittent claudication
• Palpitations

Signs:

• Pallor
• Tachycardia
• Systolic flow murmur
• Cardiac failure

There are specific signs found in the various different types of anaemia (discussed later). It must be emphasised that anaemia is not a diagnosis and the underlying cause must be found.

Investigations:

Peripheral blood:

• A low Hb should always be considered in relation to the:
• WBC count
• Platelet count
• Reticulocyte count (as this indicates marrow activity)
• Blood film (as abnormal RBC morphology may indicate the diagnosis)

Bone marrow:

• Examination of the bone marrow is performed to further investigate abnormalities found in the peripheral blood