Iron deficiency anemia (IDA) is the most common form of anemia. Causes include decreased iron intake, increased iron loss, and increased iron requirements.
Clinical history, presentation, and findings include fatigue, pallor, dyspnea on exertion, and pica.
Blood tests reveal microcytic, hypochromic anemia; 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 anemia as hemoglobin <13 g/dL in men aged ≥15 years, <12 g/dL in nonpregnant women aged ≥15 years, and <11 g/dL in pregnant women. Iron deficiency anemia (IDA) is the most common type of anemia. 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
- dyspnea 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 behavioral impairment
- heart failure
- recurrent infections
- vegetarian and vegan diet
- hookworm infestation
- chronic kidney disease
- celiac disease
- nonsteroidal anti-inflammatory drugs (NSAID) use
- chronic heart failure
- preterm or low birth weight
- infant feeding with cows' milk
- black women and Mexican women
- low socioeconomic status
- Helicobacter pylori infection
1st investigations to order
- hemoglobin and hematocrit
- platelet count
- red cell distribution width
- peripheral blood smear
- reticulocyte count
- serum iron
- total iron-binding capacity
- transferrin saturation
- serum ferritin
- celiac serology
- Helicobacter pylori testing
Investigations to consider
- hemoglobin electrophoresis
- urease breath test
- autoimmune gastritis testing
- upper gastrointestinal endoscopy (esophagogastroduodenoscopy)
- small-bowel biopsy
- lower gastrointestinal endoscopy (colonoscopy)
- CT colonography
- transferrin receptor-ferritin index
- bone marrow biopsy
- monitored trial of iron
- fecal occult blood tests
- urinary hepcidin
- percentage of hypochromic erythrocytes
- reticulocyte hemoglobin 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.
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- Guidelines for the management of iron deficiency anaemia in adults
- AGA Clinical Practice Guidelines on the gastrointestinal evaluation of iron deficiency anemia
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