The impact of anaemia on your health

Dr Lau Pik Onn / 25 May, 2020

What is anaemia?What is anaemia?

Anaemia is a condition which occurs when you have a deficiency of haemoglobin. This is an iron rich protein and is what gives blood its red colour. Haemoglobin enables red blood cells to carry oxygen from the lungs to tissue throughout your body. Red blood cells are produced regularly in the bone marrow. To produce haemoglobin and red blood cells, the body needs iron, B12, folate and other nutrients.

If you have anaemia, this means your body does not have enough healthy red blood cells to carry adequate oxygen to the tissues in your body which can make you feel tired and weak.

Anaemia affects more than 1.6 billion people around the world.1 The most common cause of anaemia in Singapore is iron deficiency.

Causes of anaemiaCauses of anaemia

Anaemia occurs when your blood does not have enough red blood cells to function normally. This is generally divided into:

  • Decreased production of red blood cells
  • Increased loss or destruction of red blood cells
  • Abnormally formed haemoglobin or red blood cells

Types of anaemiaTypes of anaemia

There are many different types of anaemia. These may be temporary or permanent and effects can range from mild all the way through to life threatening.

Iron deficiency anaemia

  • This is the most common form of anaemia and occurs when there is a shortage of iron in the body.
  • Iron deficiency anaemia may occur when there is insufficient iron due to diet or blood loss (such as from heavy menstrual flow, ulcer, cancer, bleeding piles or regular use of over the counter pain relievers, like aspirin, which can cause inflammation of the stomach and consequently blood loss). Iron deficiency anaemia commonly occurs in pregnant women.

Vitamin deficiency anaemia

  • Vitamin deficiency anaemia takes two different forms:
    • Megaloblastic anaemia – Decreased red blood cell production caused by a lack of folate or B12 in your diet
    • Pernicious anaemia – Occurs in people who consume enough B12 but are not able to absorb it

Anaemia of chronic disease

  • Anaemia may be caused by diseases like rheumatoid arthritis, kidney failure, Crohn’s disease, cancer, and other acute or chronic inflammatory diseases which can interfere with the production of red blood cells.

Aplastic anaemia

  • A rare, life threatening form of anaemia where your bone marrow is unable to produce enough red blood cells, white blood cells and platelets. This may be caused by infections, certain medications, autoimmune diseases and exposure to toxic chemicals.

Anaemia associated with bone marrow diseases (such as leukaemia)

  • These diseases affect blood production in the bone marrow, resulting in anaemia.

Haemolytic anaemia

  • Haemolytic anaemia happens when red blood cells are excessively destroyed faster than the bone marrow can replace them.

Sickle cell anaemia

  • An inherited form of anaemia which results in defective haemoglobin that force red blood cells to assume an abnormal crescent (sickle) shape.
  • These irregularly shaped blood cells then die prematurely, leading to a chronic shortage of red blood cells.


  • An inherited blood disorder that causes your body to have less haemoglobin than normal.
  • This can range from mild to severe.

How is anaemia diagnosed?How is anaemia diagnosed?

Diagnosis is based on:

  • Full medical and family history
  • Physical examination
  • Blood tests such as Full blood count, serum iron, ferritin, B12, folic acid and stool for occult blood.
  • Further tests such as bone marrow biopsy may be ordered in more complex cases

Anaemia is occasionally diagnosed during a routine blood test in people who are unaware that they may have anaemia and do not experience any symptoms.

Signs and symptoms of anaemiaSigns and symptoms of anaemia

There may not be any obvious symptoms in early cases of anaemia.

In chronic anaemia, the body can adjust to the low oxygen levels and you may not feel any differently unless the anaemia becomes severe. However, if the anaemia occurs rapidly (acute), you will experience significant symptoms relatively quickly.

Some symptoms include:

  • Fatigue and weakness

  • Trouble concentrating

  • Pale skin

  • Shortness of breath

  • Feeling dizzy or light headedness

  • Irregular heartbeat

  • Chest pain

  • Cold hands and feet

  • Headaches

  • Hair loss

What puts you at higher risk of anaemia?What puts you at higher risk of anaemia?

There are many different lifestyle, genetic and health-related risk factors that can put you at an increased risk of anaemia. These include:

  • Poor diet lacking in iron and vitamins such as folate and B12
  • Intestinal disorders that affect the absorption of nutrients in the small intestine (e.g. Crohns disease)
  • Menstrual disorders (e.g. endometriosis, fibroids that leads to heavy menstrual flow)
  • Pregnancy – this increases your risk of iron deficiency due to higher blood volume during pregnancy and the developmental demands from growing foetus (if not taking multivitamins with folic acid and iron)
  • Chronic conditions (e.g. kidney failure, rheumatoid arthritis, cancer, slow chronic blood loss from ulcer)
  • Family history of inherited anaemia (e.g. thalassemia, sickle cell)
  • Other factors like alcoholism, exposure to toxic chemicals, use of some medications
  • Age – people above age 65 years old are at a higher risk of anaemia due to poor diet

Will anaemia affect me long term?Will anaemia affect me long term?

If left untreated, long term anaemia can lead to

  • Severe fatigue
  • Pregnancy complications (e.g. premature birth)
  • Heart problems (e.g. rapid and irregular heartbeats as the heart has to pump more blood to make up for lack of oxygen, which can lead to an enlarged heart or a heart failure)

Prevention and treatment of anaemiaPrevention and treatment of anaemia

Treatment or prevention will depend on the kind of anaemia you have. Some forms of anaemia cannot be prevented.

Iron deficiency anaemia

  • This condition can be treated with a diet that is high in iron, iron supplements or through blood transfusion in severe cases.
  • Iron rich foods include red meats such as beef, beans, lentils, iron fortified cereals, dark green leafy vegetables and dried fruits. Vitamin C supplementation will also help in iron absorption.
  • The average recommended daily allowance (RDA) of iron for women is 19mg.

Vitamin deficiency anaemia

  • This is treated with adequate dietary B12 or folate and nutritional supplements
  • In some cases, B12 injections are required for pernicious anaemia
  • Foods high in folate are fruits and fruit juices, dark green leafy vegetables, green peas, kidney beans, peanuts, eggs, and enriched grain products like bread, cereal, pasta and rice
  • Foods high in B12 include meat, dairy products, fortified cereal, and soy, fish and eggs

Anaemia of chronic disease

  • There is no specific treatment for anaemia symptoms alone. The primary focus is to treat the underlying condition

Aplastic anaemia

  • Treatment may include blood transfusions to boost red blood cell count or bone marrow transplant

Hemolytic anaemia

  • Treatment includes medications to suppress the immune system such as steroids, and removal of the enlarged spleen if necessary


For a full list of references, click here.
  1. World Health Organisation. (2008). Global anaemia prevalence and number of individuals affected. Retrieved on 13 May 2020 from
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