Iron deficiency anaemia

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 a condition in which the number of red blood cells or the haemoglobin concentration within them is lower than normal.[1]World Health Organization. Anaemia. 2025 [internet publication]. https://www.who.int/news-room/fact-sheets/detail/anaemia  Haemoglobin cutoffs are employed to define anaemia in individuals and populations: <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.[2]World Health Organization. Guideline on haemoglobin cutoffs to define anaemia in individuals and populations. 2024 [internet publication]. https://www.who.int/publications/i/item/9789240088542

Iron deficiency anaemia (IDA) is the most common type of anaemia.[3]World Health Organization. The global prevalence of anaemia in 2011. 2015 [internet publication]. https://apps.who.int/iris/handle/10665/85839 [4]Kassebaum NJ, Jasrasaria R, Naghavi M, et al. A systematic analysis of global anemia burden from 1990 to 2010. Blood. 2014 Jan 30;123(5):615-24. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3907750 http://www.ncbi.nlm.nih.gov/pubmed/24297872?tool=bestpractice.com ​ Causes include decreased iron intake, increased iron loss, and increased iron requirements. The cause is unknown in some cases.