Iron Deficiency Anaemia

What is Iron Deficiency Anaemia?

Iron is necessary for the formation of haemoglobin (Hb), which is needed to carry oxygen around the body. A lack of iron can lead to a drop in the amount of haemoglobin in the red blood cells, resulting in small deformed red blood cells and a low Hb count.

It is the primary cause of anaemia, as it indicates blood loss or low iron intake which is treatable with oral/parenteral iron therapy.


Mild anaemia often has no symptoms, but if the Hb level drops too low, this will result in symptoms of anaemia. These symptoms include tiredness, dizziness, and shortness of breath. If the person has underlying heart disease, the anaemia may even cause chest pain.


If you have symptoms suggestive of anaemia, or even if you are found on a routine health screening to have a low Hb, do seek medical attention. Your doctor will take a full history and perform a physical examination, including looking for pallor. He will then order further blood tests.  


Iron deficiency anaemia can be due to ongoing blood loss from the digestive tract – this includes the oesophagus, stomach, small intestines and colon. In most cases, the patient may not have any symptoms at all. The ongoing blood loss may or may not manifest as blood in the stool. Iron deficiency anaemia can sometimes be due to blood loss from frequent and heavy menstruation. Malnutrition and parasitic infection can also cause iron-deficiency anaemia in developing countries – as a result of poor intake or poor absorption of iron.


Low iron intake due to malnutrition or by choices (e.g. a vegan diet) are common causes of iron deficiency that are easily corrected and identified. Heavy menses is a common cause of blood loss in women.

In the gut, being on blood thinners or antiplatelet agents or taking non-steroidal anti-inflammatory drugs (NSAIDS) such as ibuprofen, naproxen and mefenamic acid are risk factors for developing gastritis and ulcers that may cause silent blood loss and anaemia.


Blood tests are taken to confirm anaemia, and to measure the ferritin, iron, and TIBC (total iron binding capacity). Your doctor may also do additional tests to exclude other causes of anaemia such as thalassemia. 

Doctors would often need to perform gastroscopy and colonoscopy to exclude serious diseases such as cancer of the stomach or colon. Sometimes, the bleeding may be from the small intestine. This requires specialised tests such as video capsule endoscopy and small intestine enteroscopy to evaluate the gut


After identifying and addressing the underlying cause, your doctor will prescribe oral iron supplements to replenish the iron stores in your body. Treatment could also be an intravenous iron infusion if the anaemia is severe. If the Hb is very low, an urgent blood transfusion may be necessary.