Iron deficiency anaemia (IDA) is the most common form of anaemia. Causes include decreased iron intake, increased iron loss, and increased iron requirements.
Clinical history, presentation, and findings include fatigue, pallor, dyspnoea on exertion, and pica.
Blood tests reveal microcytic, hypochromic anaemia; low reticulocyte count.
Other laboratory findings include low serum iron, increased total iron-binding capacity (TIBC), less than 16% transferrin saturation, and low serum ferritin.
Diagnosis of IDA requires investigation of the underlying cause.
Treatment includes oral or intravenous iron replacement.
The World Health Organization (WHO) defines anaemia as haemoglobin <130 g/L (13 g/dL) in men aged ≥15 years, <120 g/L (12 g/dL) in non-pregnant women aged ≥15 years, and <110 g/L (11 g/dL) in pregnant women. Iron deficiency anaemia (IDA) is the most common type of anaemia. Causes include decreased iron intake, increased iron loss, and increased iron requirements. The cause is unknown in some cases.
History and exam
Key diagnostic factors
- dyspnoea on exertion
- restless legs syndrome
- nail changes
Other diagnostic factors
- impaired muscular performance
- glossitis and angular stomatitis
- hair loss
- rectal lesion on examination
- growth impairment
- cognitive and behavioural impairment
- heart failure
- recurrent infections
- vegetarian and vegan diet
- hookworm infestation
- chronic kidney disease
- coeliac disease
- non-steroidal anti-inflammatory drug (NSAID) use
- chronic heart failure
- premature or low birth weight
- infant feeding with cows' milk
- black women and Mexican women
- low socioeconomic status
- Helicobacter pylori infection
1st investigations to order
- haemoglobin and haematocrit
- platelet count
- red cell distribution width
- peripheral blood smear
- reticulocyte count
- serum iron
- total iron-binding capacity
- transferrin saturation
- serum ferritin
- coeliac serology
- Helicobacter pylori testing
Investigations to consider
- haemoglobin electrophoresis
- urease breath test
- autoimmune gastritis testing
- upper gastrointestinal endoscopy (oesophagogastroduodenoscopy)
- small-bowel biopsy
- lower gastrointestinal endoscopy (colonoscopy)
- CT colonography
- transferrin receptor-ferritin index
- bone marrow biopsy
- monitored trial of iron
- faecal occult blood tests
- urinary hepcidin
- percentage of hypochromic erythrocytes
- reticulocyte haemoglobin content
- erythrocyte protoporphyrin
Atul Mehta, MD
Lysosomal Storage Disorders Unit
Department of Haematology
Royal Free Hospital
AM has received honoraria, travel, and research grants from Sanofi/Genzyme, Shire/Takeda/Amicus and Protalix/Pfizer; all of these companies manufacture pharmaceutical therapies for the treatment of lysosomal disorders.
Dr Atul Mehta would like to gratefully acknowledge Dr Martina Murphy, Dr Marc Zumberg, and Dr Rebecca Fischer Connor, previous contributors to this topic.
MZ declares that he is medical director for NCF Diagnostics and DNA Technologies, and a consultant for Alexion Pharmaceuticals. MM and RFC declare that they have no competing interests.
Carlos Aravena, MD
Internal Medicine Instructor
Member of Evidence Based Medicine Unit
Catholic University of Chile
CA declares that he has no competing interests.
Jim Murray, MBBS
University Hospital Birmingham NHS Trust
JM declares that he has no competing interests.
Ajay Kumar, MD, FACP
AK has received a fee for speaking about perioperative blood management from Ortho-Biotech, and has also received reimbursement from medscape.com for the education webcast of the same presentation.
- Anaemia of chronic disease
- Disorders of globin synthesis (thalassaemias, haemoglobin E, haemoglobin C, unstable haemoglobins)
- Sideroblastic anaemias
- Guidelines for the management of iron deficiency anaemia in adults
- Chronic kidney disease: assessment and management
Anaemia, iron deficiencyMore Patient leaflets
- Log in or subscribe to access all of BMJ Best Practice
Use of this content is subject to our disclaimer