Is anaemia that is caused by blood loss more life-threatening?

• It depends on the rate and volume of blood loss and the fitness of the individual. Sudden, rapid and ongoing blood loss can be life-threatening.
• If blood loss is slow and over a long period of time (eg. over a few months), the patient may not even experience any symptoms until the blood level has dropped considerably.
• Anaemia that causes a sudden rapid drop in red blood cells, such as haemolytic anaemia (red blood cell breakdown) can also be life threatening as there is no time for the body to compensate.  There is no one cause of anaemia that is more life threatening than another. The cause needs to be identified early such that treatment can stop the blood loss and supportive transfusions can be given in the meantime.  

How common is anaemia in Singapore?

• In a study (Sahadevan et al. 1995) of hospitalized patients above 65 years of age, about 1 in 3 patients (35.8%) were found to be anemic. More males (55.6%) than females (44.4%) have anaemia.
• In the younger age group, iron deficiency anaemia is more common in females than males. Iron deficiency anaemia in younger females is mainly due to excessive menstrual loss with inadequate iron replacement which may go untreated or undetected.
• Anaemia is a World Bank development indicator. In 2016, it was reported that 22% of non-pregnant women between the ages of 15-49 had anaemia in Singapore. Among pregnant women, 31% had anaemia. 

Who are more prone to anaemia? Why?

• Causes of anaemia are wide ranging and there are several groups that are more prone to have anaemia. In women who have their menses, iron deficiency anaemia is common. In pregnant women, anaemia can occur due to dietary deficiencies and increased blood volume.
• In older patients with multiple medical problems or kidney disease, there is underproduction of red blood cells by the bone marrow due to inflammation, suppression, or lack of erythropoietin (which is a hormone produced by the kidneys to stimulate red blood cell production).
• Patients with malignancies may have anaemia due to the disease or due to medications that suppress the bone marrow.
• A common inherited anaemia in Singapore is thalassemia where abnormal production of haemoglobin results in anaemia. About 4% of our population are carriers of the thalassemia gene.  A large proportion have thalassemia minor (thalassemia trait) with mild or undetectable anaemia and can lead a normal life. A small proportion have thalassemia major or intermedia that require blood transfusion. The risk of thalassemia major increases when both parents are carriers of the thalassemia gene. Therefore, screening is recommended for couples that are planning to start a family.