Iron-deficiency anaemia (anemia) is the commonest form of anaemia (shortage of blood). Specifically it is a shortage of haemoglobin, the red pigment in red blood cells that carries oxygen. The shortage makes you short of breath and feel weak and exhausted. When severe it can cause heart failure. In infants it can cause delayed mental development and impaired performance on language skills and motor skills, including co-ordination. It can reduce children's learning and thinking ability (cognitive impairment).
Iron is needed by everyone to make haemoglobin. You need more iron if you growing rapidly, pregnant, or loosing blood. Iron-deficiency anaemia occurs in many illnesses and in women from bleeding with heavy periods (menstruation).
Most of the iron in food is in a form that is poorly absorbed, but the iron in meat is absorbed better than that from plants. Individually iron-deficiency anaemia is caused caused by the persons particularly high need for iron, but territorily it is caused by the levels of dietary iron and lack treatment with iron supplements. In rich countries, some food products have added iron content. Good antenatal care includes giving iron supplements when needed.
Iron-deficiency anaemia caused 0.24% of all deaths worldwide in 2002, an average of 22 deaths per million people per year.