Anaemia refers to the medical condition that occurs when you have a low number of red blood cells or reduced haemoglobin in the red blood cells in your body. This results in the body’s inability to transport enough oxygen to your tissues. 

If you have anaemia, your heart might have to work harder to pump the quantity of blood needed to circulate enough oxygen throughout your body. Without adequate oxygen, the cells in your body struggle to do what they’re supposed to.

There are many types of anaemia - an estimated 400 types divided into three groups - and each type has its own specific cause. While this condition is relatively common, most people aren’t aware of the underlying cause for their condition even after experiencing symptoms for years.

With an estimated 1.62 billion people affected globally and the incidence of people affected supposedly increasing each year, it’s important to learn more about what causes this condition, the signs and symptoms you should look out for, and other risk factors related to anaemia.  


With the presence of many types of anaemia and the absence of a specific, underlying cause, it can be difficult to pinpoint the exact cause of this condition. However, the consensus is that there are three main types of anaemia and that there are common and identifiable causes for each type. 

Anaemia caused by blood loss

Iron deficiency anaemia is the most common type of anaemia and is one caused by blood loss. This results in a shortage of iron in your blood. Anaemia caused by blood loss could be due to: 

  • Gastrointestinal conditions such as ulcers, haemorrhoids, gastritis or cancer
  • Use of non-steroidal anti-inflammatory drugs such as aspirin and ibuprofen
  • Crohn's disease
  • Surgical removal of part of the gut
  • Heavy menstrual bleeding

Anaemia caused by decreased or faulty red blood cell production

Red blood cells are produced in the bone marrow. If there is an onset of any of the diseases that affect the bone marrow, this can disrupt the production of red blood cells resulting in anaemia. These include:

  • Leukaemia, where too many abnormal white blood cells are produced
  • Aplastic anaemia, where the bone marrow doesn’t make red blood cells
  • Myeloproliferative disorders, where the bone marrow produces too many white blood cells
  • Other types of anaemia such as sickle cell anaemia and vitamin-deficiency anaemia

Anaemia caused by the destruction of red blood cells

Red blood cells typically have a lifespan of 120 days but due to various reasons, they could be destroyed or removed. This can occur due to:

  • Infections
  • Certain drugs
  • Animal venom
  • An autoimmune attack


Signs and symptoms of anaemia may vary depending on its cause and may even display no symptoms. The most common symptom across all types of anaemia is experiencing fatigue and a lack of energy. Other symptoms include:

  • Pale skin
  • Shortness of breath
  • Dizziness
  • Headache
  • Chest pain
  • Cold hands and feet

Other types of anaemia result in more specific symptoms such as:  

  • Aplastic anaemia - fever, skin rashes, and frequent infections
  • Folic acid-deficiency anaemia - irritability, diarrhoea, and a smooth tongue
  • Haemolytic anaemia - jaundice, dark urine, fever, and abdominal pain
  • Sickle cell anaemia - painful swelling of the feet and hands and jaundice

It’s also important to incorporate more fruits and vegetables into daily meals, opt for whole-grain bread and cereals, chew food properly, and eat slowly.

Risk factors

Anaemia can occur in people of all genders, ages, and racial backgrounds. However, some may be at greater risk of anaemia than others due to factors such as:

  • Pregnancy and childbirth
  • Menstruation
  • Intestinal disorders such as Crohn's disease and coeliac disease
  • Chronic conditions such as cancer, kidney failure, diabetes, AIDS, and ulcers
  • A diet lacking in vitamins, minerals, and irons, such as B-12 and folate
  • Premature birth
  • Family history of inherited anaemia such as sickle cell anaemia
  • Being over 65 years of age
  • Medical history of autoimmune diseases, infections and the consumption of certain drugs
  • Alcoholism

Request information on the causes, symptoms and risk factors of anaemia


The symptoms, causes and risk factors of anaemia can vary from person to person.

For more information on the causes and treatment options for anaemia, consult Dr Suhirdan Vivekanandarajah, an interventional gastroenterologist and hepatologist in Sydney.

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