Anaemia: migrant health guide
Advice and guidance on the health needs of migrant patients for healthcare practitioners.
Main messages
Anaemia affects approximately one third of the world’s population.
Anaemia is the result of a wide variety of causes that commonly co-exist. Globally the most significant factor causing anaemia is iron deficiency.
Where you find a migrant patient to be anaemic, investigate as for any other patient. The determination of the cause is assisted by the size of the red blood cells: microcytic, normocytic, or macrocytic.
Certain causes of anaemia may be particularly pertinent to some migrant patients, including iron deficiency, other nutritional deficiencies such as folate or vitamins B12 and A, haemoglobin disorders (sickle-cell disease and thalassaemias), and a wide range of infections to which some migrants may be at higher risk for, such as tuberculosis (TB), HIV, malaria and other parasitic infections.
Further laboratory investigations can help to differentiate the causes of anaemia and discuss with your local haematology laboratory as appropriate.
Treat anaemia based on its underlying cause.
The NHS antenatal screening programmes test for anaemia and haemoglobin disorders.
Background
The blood haemoglobin threshold levels for anaemia can be found in the NICE (National Institute for Health and Care Excellence) guidelines.
Classification and causes
You should investigate migrant patients for anaemia in the same way that you would investigate any other patient.
Anaemia is the result of a wide variety of causes that commonly co-exist, and is commonly classified according to the size of the red blood cells: microcytic, normocytic and macrocytic.
Certain causes of each type are relevant to consider in some migrant patients.
Microcytic
The main causes of microcytic anaemia to consider include:
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iron deficiency anaemia — the most common cause of anaemia, probably accounting for around 50% of all anaemia globally, its main causes are:
- dietary deficiency of iron
- bleeding in the stomach and intestines which can be caused by a stomach ulcer, stomach cancer, bowel cancer, or by taking non-steroidal anti-inflammatory drugs (NSAIDs)
- malabsorption of iron due to gastro-intestinal problems, or a diet high in phytates (for example legumes and whole grains) or phenolic compounds (eg tannins in tea and wine)
- blood loss eg due to heavy menstruation or chronic parasitic infestation (for example hookworm, schistosomiasis, ascariasis), which can also lead to blood loss in people from the tropics
- increased demands for iron eg during growth and pregnancy
- Thalassaemias — a haemoglobin disorder
- anaemia of chronic disease — can include chronic infections such as tuberculosis (TB) and HIV
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lead poisoning — products used by some migrants which have a high concentration of lead include:
- some imported cosmetic products eg eye kohl
- Calabash Chalk, also known as Calabar stone, La Craie, Argile, Nzu or Mabele, which is a traditional remedy for morning sickness used by some migrant women (West African, particularly Nigerian, and some Asian).
See non-infectious environmental hazard examples.
Normocytic
The main causes of normocytic anaemia to consider include:
- anaemia of chronic disease — can include chronic infections such as tuberculosis (TB) and HIV
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haemolytic anaemia — causes may include:
- haemoglobin disorders (sickle cell disease, Thalassaemias)
- inherited red cell enzyme deficiencies eg glucose-6-phosphate dehydrogenase (an x-linked disorder common in the Mediterranean, the Middle East, South East Asia and West Africa), and pyruvate kinase deficiency (common in Northern European populations)
- haemolytic infections, including malaria
- riboflavin deficiency
Macrocytic
The main causes of macrocytic anaemia to consider include:
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vitamin B12 deficiency, usually the result of:
- pernicious anaemia in high income countries
- dietary insufficiency in low income countries, particularly for those with a vegan diet
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folate deficiency
Other micronutrient deficiencies can increase the risk of anaemia, such as:
- vitamin A
- copper
Macrocytic anaemia is also frequently linked to alcoholism, with or without liver disease.
Testing and treatment
Maintain vigilance for anaemia in at-risk people and investigate as normal, while bearing in mind that some migrants may be at increased risk of particular causes of anaemia.
Further laboratory investigations can help to differentiate the causes of anaemia and discuss with your local haematology laboratory as appropriate.
Treat anaemia on the basis of its underlying cause.
Antenatal screening
The UK National Screening Committee policy is to offer all pregnant women a test for anaemia.
In addition, NICE guidelines recommend offering antenatal screening for sickle cell diseases and thalassaemias to all women as early as possible in pregnancy, preferably by 10 weeks of gestation.
Preconception counselling (supportive listening, advice giving and information) and carrier testing should be available to all women who are identified as being at higher risk of haemoglobinopathies, using the family origin questionnaire from the NHS antenatal and newborn screening programme.
Resources
NHS.UK provides further information on iron deficiency anaemia.
The NHS Sickle Cell and Thalassaemia screening programme has published a number of publications in a range of languages.
NICE has produced clinical knowledge summaries on anaemia.
Last updated 20 May 2021 + show all updates
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Updated advice and guidance on anaemia, including new links to additional resources.
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First published.