WHAT IS ANAEMIA?

Figure
A: Distribution of haemoglobin values (Hb) in a hypothetic population of women where all have their individual optimal value. By definition 2.5% have Hb-values lower than 120 g/L. The 2.5 - percentile = mean - 1.96 SD (= lower 95% CI).

B: Distribution of haemoglobin values (Hb) in a hypothetic population of children (age ½-6 years) where all have their individual optimal value.By definition 5% have Hb-values lower than 110 g/L. The 5-percentile = mean - 1,645 SD

With lower haemoglobin values(*) anaemia is probable(**)

(*At sea level **WHO, 1959-98) [Ref 18]

Common symptoms of anaemia

• lassitude (= Norwegian matthet) and fatigue, headache
• breathlessness, insomnia
• dizziness, pallor (= Norwegian blekhet) of skin, dimness of vision

Physical signs

• pallor of mucous membranes and finger nails
• tachycardia (elevated heartbeat frequency)
• oedema (in severe cases of anaemia)
• cardiac arrest (in severe cases of anaemia)

Causes of Anaemia

• Iron deficiency
• Vitamin B₁₂ - deficiency (e.g.,intrinsic factor deficiency)
• Folate deficiency
• Increased haemolysis
• Decreased bone marrow activity
• Defective haemoglobin synthesis

Note that anaemia is defined by Hb below cut-off values.

Iron deficiency is the most common cause of anaemia.