• Confirm the diagnosis of iron deficiency anaemia.
• Assess the person to determine the cause and severity of anaemia.
• Refer for further investigation to the appropriate speciality (e.g. gastroenterology, surgery, gynaecology).
• Treat adults with iron deficiency anaemia (including pregnant women):
• Treat the underlying cause if appropriate to do so in primary care.
• Treat iron deficiency anaemia with ferrous sulphate first-line and advise about diet.
• Monitor as appropriate.

The assessment should aim to determine whether there is an underlying cause of the iron deficiency anaemia, and whether the person has any complications, through history, examination, and appropriate investigations.

• Diet (to identify poor iron intake).
• Drug history (e.g. aspirin, nonsteroidal anti-inflammatory drugs, selective serotonin reuptake inhibitors, clopidogrel, and corticosteroids).
• History of overt bleeding or blood donation.
• Menstrual history (if appropriate).
• History of recent illness which might suggest underlying gastrointestinal bleeding:
• Gastrointestinal symptoms (including altered bowel habit).
• Weight loss.
• Travel history (increased risk of hookworm in travellers to the tropics).
• Family history:
• Iron deficiency anaemia (which may indicate inherited disorders of iron absorption).
• Haematological disorders (e.g. thalassaemia).
• Bleeding disorders and telangiectasia.
• If the anaemia is severe, ask about specific cardiac symptoms (e.g. angina, dysrhythmias, and ankle swelling).

• To determine whether there is an underlying cause for the anaemia, and whether the person has developed complications:
• Examine the abdomen and perform a rectal examination (particularly looking for masses).
• Examine the cardiovascular system and chest for signs of heart failure.
• If heavy menstrual bleeding is thought to be the cause of iron deficiency anaemia, see the CKS topic on Menorrhagia.

• Confirm the diagnosis of iron deficiency anaemia, if this has not already been done.
• It is usually unnecessary to investigate the following groups of people prior to treatment:
• Otherwise healthy young people in whom the history clearly suggests a cause (e.g. regular blood donors).
• Menstruating young women with no history of gastrointestinal symptoms or family history of colorectal cancer.
• Pregnant women — investigations (to determine an underlying cause or the presence of complications) are not usually needed if anaemia develops during pregnancy unless the anaemia is severe, the history and examination suggest an alternative cause of iron deficiency (e.g. inflammatory bowel disease), or there is no response to iron supplementation.
• People who are terminally ill or unable to undergo invasive investigations — the appropriateness of investigating people with severe comorbidity (or, in some circumstances, advanced age), especially if management would not be influenced by the results, should be discussed with the person and their family and carers.
• People who refuse further investigations.
• Ideally the likely cause should be documented (e.g. menstruation, frequent blood donation).
• If there is a poor response to empirical iron treatment, or recurrence of anaemia without an obvious cause, the person should be investigated further.
• For other groups of people with iron deficiency anaemia, consider:
• Testing the urine for blood.
• Screening for coeliac disease using coeliac serology (presence of anti-endomysial antibody or tissue transglutaminase antibody).
• Referral for upper and lower gastrointestinal (GI) investigations. For information on when to refer for upper and lower GI investigations, see Referral, or seeking specialist advice.
• Stool examination to detect parasites if appropriate from the person's travel history.
• See the CKS topic on Menorrhagia for information on appropriate investigations if a woman has heavy menstrual bleeding.

• For people of any age with dyspepsia who present with iron deficiency anaemia — refer urgently (within 2 weeks) for endoscopy, or to a specialist with expertise in upper gastrointestinal cancer.
• For people with iron deficiency anaemia without dyspepsia — recognize the possibility of upper gastrointestinal cancer and consider urgent referral for further investigations.
• For men of any age with unexplained iron deficiency anaemia and a haemoglobin level of 11 g/dL or below — refer urgently (within 2 weeks) to a gastroenterologist.
• For women who are not menstruating, with unexplained iron deficiency anaemia and a haemoglobin level of 10 g/dL or below — refer urgently (within 2 weeks) to a gastroenterologist.
• People with unexplained iron deficiency anaemia who do not fulfil these criteria for urgent referral will still require referral for further investigation. The urgency of this will require clinical judgement based on the haemoglobin level and clinical findings.
• Other situations in which specialist expertise is required include:
• If the person has profound anaemia with signs of heart failure — admit to hospital.
• If a woman with menorrhagia has iron deficiency anaemia that has failed to respond to treatment — refer to a gynaecologist (urgency of referral should reflect clinical judgement).
• If a person is unable to tolerate, or is not responding to, oral iron treatment — seek specialist advice.
• If a person who has initially responded to iron treatment develops anaemia again without an obvious underlying cause — seek specialist advice regarding further assessment and investigation.

• Address underlying causes as necessary (e.g. treat menorrhagia, stop nonsteroidal anti-inflammatory drugs if possible).
• Treat with oral ferrous sulphate 200 mg tablets two or three times a day.
• If ferrous sulphate is not tolerated, consider oral ferrous fumarate tablets or ferrous gluconate tablets.
• Do not wait for investigations to be carried out before prescribing iron supplements.
• If dietary deficiency of iron is thought to be a contributory cause of iron deficiency anaemia, advise the person to maintain an adequate balanced intake of iron-rich foods (e.g. dark green vegetables, iron-fortified bread, meat, apricots, prunes, and raisins) and consider referral to a dietitian.
• Monitor the person to ensure that there is an adequate response to iron treatment.

• Recheck haemoglobin levels (full blood count) after 2–4 weeks to assess the person's response to iron treatment.
• If there is a lack of response, see Inadequate benefit from initial iron treatment.
• If there is a response check the full blood count at 2–4 months to ensure that the haemoglobin level has returned to normal.
• Once haemoglobin concentration and red cell indices are normal:
• Continue iron treatment for 3 months to aid replenishment of iron stores and then stop.
• Then monitor the person's full blood count every 3 months for 1 year.
• Recheck after a further year.
• If haemoglobin or red cell indices drop below normal, give additional iron.
• Consider an ongoing prophylactic dose in people who at particular risk of iron deficiency anaemia.

• Assess compliance and whether the iron treatment is tolerated.
• If an oral iron supplement (usually ferrous sulphate) is not tolerated, then address adverse effects by:
• Offering a laxative to people with constipation.
• Offering reassurance to people who have black stools.
• Recommending the person takes iron with or after meals.
• Reducing the dose frequency of the iron supplement (i.e. one or two tablets daily).
• Giving a different iron formulation or salt with a lower content of elemental iron (e.g. ferrous gluconate).
• If the person is still unable to tolerate oral iron supplements, seek specialist advice.
• People should undergo specialist assessment if there is a lack of response (increase of less than 2 g/dL in the haemoglobin level) after 2–4 weeks.