The three main causes of anaemia are:
- losing too much blood
- not making enough healthy red blood cells
- the destruction of too many red blood cells.
Losing too much blood
This is a common cause of anaemia. Situations where too much blood can be lost include:
- when women have heavy bleeding during their periods
- stomach ulcers or other problems that cause bleeding inside the body
- blood loss from surgery or an injury.
Not making enough red blood cells
Your body may not make enough red blood cells if your diet is lacking in nutrients (eg, iron, folic acid, vitamin B12, and vitamin C) or is not able to absorb these nutrients properly from the gut.
- The most common cause of anaemia is iron-deficiency from low iron intake or increased blood loss.
- Vitamin B12 or B9 (commonly called folate) deficiency. This causes the body to produce abnormally large red blood cells that cannot function properly.
- Sometimes a long-term disease keeps your body from making enough red blood cells such as kidney disease, arthritis, diabetes or cancer.
- Your body may not produce enough red blood cells during pregnancy when extra red blood cells are needed for the growing baby.
Destroying too many red blood cells
Red blood cells last about 3–4 months in the body. In some situations, the red blood cells are damaged or destroyed more quickly than normal. Examples are when you have a disease such as sickle cell disease or thalassemia or have certain medical treatments, eg, chemotherapy.
