Anaemia

Anaemia is a condition in which the number of red blood cells or the haemoglobin concentration within them is lower than normal. Haemoglobin is needed to carry oxygen and if you have too few or abnormal red blood cells, or not enough haemoglobin, there will be a decreased capacity of the blood to carry oxygen to the body’s tissues. This results in symptoms such as fatigue, weakness, dizziness and shortness of breath, among others. The optimal haemoglobin concentration required to meet physiologic needs varies by age, sex, elevation of residence, smoking habits and pregnancy status.  Anaemia may be caused by several factors: nutrient deficiencies through inadequate diets or inadequate absorption of nutrients, infections (e.g. malaria, parasitic infections, tuberculosis, HIV), inflammation, chronic diseases, gynaecological and obstetric conditions, and inherited red blood cell disorders. The most common nutritional cause of anaemia is iron deficiency, although deficiencies in folate, vitamins B12 and A are also important causes. 

Anaemia is a serious global public health problem that particularly affects young children, menstruating adolescent girls and women, and pregnant and postpartum women. WHO estimates that 40% of children 6–59 months of age, 37% of pregnant women, and 30% of women 15–49 years of age worldwide are anaemic.

Anaemia can cause a range of non-specific symptoms including tiredness, weakness, dizziness or light-headedness, drowsiness, and shortness of breath, especially upon exertion. Children and pregnant women are especially vulnerable, with more severe cases of anaemia leading to an increased risk of maternal and child mortality. Iron deficiency anaemia has also been shown to affect cognitive and physical development in children and reduce productivity in adults.

Anaemia is an indicator of both poor nutrition and poor health. It is problematic on its own, but it can also impact other global public health concerns such as stunting and wasting, low birth weight and childhood overweight and obesity due to lack of energy to exercise. School performance in children and reduced work productivity in adults due to anaemia can have further social and economic impacts for the individual and family. 

Accurate characterization of anaemia is critical to understand the burden and epidemiology of this problem, for planning public health interventions, and for clinical care of people across the life course. While iron deficiency anaemia is the most common form and can often be treated through dietary changes, other forms of anaemia must be treated by addressing underlying infections and chronic conditions requiring comprehensive health interventions.

WHO has guidance that covers all WHO Regions to help reduce the prevalence of anaemia through prevention and treatment. These guidelines aim to increase dietary diversity, improve infant feeding practices and improve the bioavailability and intake of micronutrients through fortification or supplementation with iron, folic acid and other vitamins and mineral. Social and behaviour change communication strategies are used to change nutrition-related behaviours. Interventions to address the underlying and basic causes of anaemia look at issues such as disease control, water, sanitation and hygiene, reproductive health and root causes such as poverty, lack of education and gender norms.  

Anaemia, as a public health issue, needs to be addressed from multiple perspectives and through multiple coordinated efforts, including multiple government sectors, nongovernmental organizations, United Nations agencies and the private sector – each with specific and complementary roles to collectively achieve anaemia reduction and improve health and well-being.

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