Iron Deficiency (Anemia)

What is iron deficiency?

Iron deficiency refers to inadequate levels of the mineral iron in the body. The term is commonly used interchangeably with anemia: a condition often caused by iron deficiency, where the body either cannot produce a sufficient number of healthy red blood cells, or enough of the protein (hemoglobin) that allows red blood cells to carry oxygen around the body. However, health problems may arise before iron levels drop to the extent that anemia develops. For this reason, the terms “iron depletion” and “non-anemic iron deficiency” are sometimes also used.[1]

Iron is a micronutrient that is vital for the healthy functioning of the body. It is an important part of the production of red blood cells, skin, hair, nails, muscles and hormones. Iron also plays a key role in the functioning of nerve cells.[2]

For many people, a balanced and varied diet provides all the iron they need. Good sources of iron include liver, meat, beans, nuts, whole grains, fortified breakfast cereals and dark-green leafy vegetables.[3]

However, iron deficiency is very common in both developing and developed countries, making it the most widespread nutritional disorder in the world.[4] Groups of people who are particularly at risk of developing iron deficiency include pregnant women, premenopausal women, infants, children, teenagers and the elderly.[1][5]

Iron deficiency may be the result of a number of different factors and conditions. Some of the most common causes of iron deficiency are inadequate dietary intake, continuous blood loss, increased need and inadequate absorption.[1][5]

Symptoms of iron deficiency do not always manifest until iron-deficiency anemia develops, but may include fatigue; paleness; dizziness; an inability to concentrate and diminished productivity; unhealthy nails, skin and hair and a painful tongue, among others.[1][5]

If left untreated, iron-deficiency anemia can have serious consequences, including increased susceptibility to illness and infection,[6] pregnancy complications, impaired cognitive and physical development, heart failure[7] and increased risk of morbidity in children.[4] However, iron deficiency is generally fairly easy to treat by addressing underlying conditions, making dietary modifications and taking supplements where necessary.[1][4][5]


Anemia means that the body doesn’t have enough healthy red blood cells and hemoglobin to transport oxygen around the body. Iron deficiency anemia is caused due to lack of iron and hemoglobin, which are needed for binding oxygen to the red blood cells. This condition may develop when the body does not have enough iron to make red blood cells. This condition often occurs after someone loses large amounts of blood or during pregnancy when the body needs more iron than normal. It can also occur slowly over time if a person can’t or doesn’t take in enough iron. Iron deficiency is one of the most common causes of anemia. This condition is most common in women of childbearing age.

Iron deficiency symptoms

Tiredness and a reduced ability to exercise may be experienced before anemia develops.[8] However, signs of low iron may not be noticeable in many people until the deficiency has advanced to anemia.[1] Even then, some people may present with few or no symptoms.[6][8] The severity of the symptoms typically depends on how rapidly anemia develops and the extent of the deficiency.[6][9]

Main symptoms

Where present, some of the more common symptoms of iron deficiency may include:[7][10][6]

  • Fatigue
  • Difficulty concentrating on work or studies
  • Memory problems
  • Headaches
  • Faintness and dizziness
  • Breathlessness
  • Reduced ability to exercise
  • Pale complexion
  • Poor condition of hair, sometimes with hair loss
  • Brittle nails that break easily, change shape or develop ridges
  • Slow-healing wounds
  • Sore, inflamed tongue
  • Sores at the corners of the mouth
  • Restless legs syndrome
  • Delayed development in babies

Less common symptoms

Some of the less common symptoms of iron deficiency may include:[6][9][11]

  • Itching
  • Tinnitus (ringing in the ears)
  • Changes in sense of taste
  • Chest pain (usually in people where there is pre-existing heart disease)
  • Craving or eating clay, chalk, coal, ice, paper or other non-food substances (Pica syndrome)
  • Difficulty swallowing (very rare)

Many of the symptoms of iron deficiency are nonspecific and may be indicative of other conditions.[12][10] In addition, there are a number of different types of anemia, all of which require different treatments. For this reason, it is important to consult with a medical practitioner should any of the above symptoms present.


The diagnosis is often based on symptoms in someone who is at risk of having an iron deficiency. Blood tests are done to investigate the number and size of red blood cells, along with the hemoglobin level and iron levels. Other tests, such as endoscopy (a flexible camera through the mouth to look at the intestine) may be needed to diagnose the cause of the iron deficiency.


If the iron deficiency anemia is a sign of another underlying disease, that condition should be treated to prevent further iron loss or problems with iron intake. If there is no problem taking in iron, people with iron deficiency should eat iron-rich foods, such as lentils, peas and beans, fish, meat, green leafy vegetables, brown rice, eggs, and dried fruits such as dried apricots and prunes. People who have low stores of iron in their body can replace iron with supplements or, if large amounts are needed, by an injection.


A balanced diet with enough iron-containing foods can help prevent iron-deficiency anemia. Pregnant women should consider taking an iron supplement to prevent this condition.

  1. Patient. “Non-anaemic Iron Deficiency.” October 20, 2014. Accessed October 25, 2017.

  2. Patient. “Iron Deficiency.” May 26, 2017. Accessed October 25, 2017.

  3. NHS Choices. “Iron.” March 3, 2017. Accessed October 27, 2017.

  4. World Health Organization. “Micronutrient deficiencies.” Accessed October 27, 2017.

  5. Better Health Channel. “Iron deficiency - adults.” September, 2014. Accessed October 27, 2017.

  6. NHS Choices. “Iron deficiency anaemia.” January 14, 2016. Accessed October 27, 2017.

  7. Patient. “Iron-deficiency Anaemia.” November 24, 2014. Accessed October 27, 2017.

  8. UpToDate. “Treatment of iron deficiency anemia in adults.” September 18, 2017. Accessed October 27, 2017.

  9. Cold Spring Harbor Perspectives in Medicine. “Iron Deficiency Anemia: A Common and Curable Disease.” July, 2013. Accessed October 29, 2017.

  10. Patient. “Iron Deficiency - Symptoms.” May 26, 2017. Accessed October 27, 2017.

  11. Patient. “Iron-deficiency Anaemia.” November 24, 2014. Accessed October 29, 2017.

  12. Health Direct. “Iron deficiency symptoms.” March, 2017. Accessed October 27, 2017.