SINGAPORE - Anaemia is a blood condition in which there is a lack of haemoglobin - the red pigment in red blood cells that carries oxygen.
Dr Daryl Tan, a specialist in haematology and a consultant at the Raffles Cancer Centre at Raffles Hospital, said that red blood cells contain lots of iron and have a lifespan of two to three months, after which they are destroyed by the spleen. But the iron is mostly recycled for the production of new red blood cells.
He said: "If we eat healthily and no blood is lost from the body, we do not develop iron deficiency. But if there is not enough iron, red blood cell production gets compromised and anaemia develops."
The rehmannia root is not widely used in conventional medicine to treat anaemia, but its high iron content may be helpful to patients with iron-deficiency anaemia, Dr Tan said .
In Singapore and other developed countries, nutritional causes of anaemia are rare, unless the patient is a strict vegetarian and is not getting vitamin B12 from meat, and hence, risks developing B12-deficiency anaemia.
In these countries, it is usually women of reproductive age who are at risk of iron deficiency. Women with gynaecological conditions, such as fibroids (non-cancerous growths in the womb), polyps (small growths that can turn cancerous), adenomyosis (which results in abnormally thick uterus walls), hormonal imbalance or have an intrauterine device for contraception may be at higher risk, Dr Tan added.
Other commonly seen causes of anaemia here include thalassaemia (an inherited condition affecting haemoglobin) and chronic disease, such as diabetes or kidney failure.
Diabetes may affect the ability of the bone marrow to respond to erythropoietin - a hormone that stimulates the bone marrow's red blood cell production - and to utilise iron stores in the body to produce red blood cells, predisposing the patient to anaemia. Kidney patients lack erythropoietin. Rarer causes of anaemia here are bone marrow diseases and blood cancer.
As doctors do not regard anaemia as a disease but see it as a symptom of an underlying problem, treatment focuses on the cause, said Dr Tan.
Patients with iron deficiency anaemia would be given iron supplements, while those with vitamin deficiency anaemia would be given vitamin B12 injections.
Patients with severe forms of thalassaemia, called thalassaemia major and thalassaemia intermedia, may require regular blood transfusions.
It is important to treat the correct underlying cause of anaemia, said Dr Tan, warning against the indiscriminate use of iron supplements such as rehmannia root if the anaemia is not caused by iron deficiency.
Excess iron in the body impairs the function of infection-fighting white blood cells and allows bacteria to thrive better, he explained.
He said: "Increasing the iron content in the body could increase a person's susceptibility to infections."
To prevent anaemia, he advised people to have a well-balanced diet. Strict vegetarians should try to get regular blood tests to see if they require vitamin B12 supplements.
Women who are menstruating should also watch out for unusual symptoms, he advised.
If they feel faint, say, when getting up from a lying position, tyre more easily than usual when climbing stairs or walking to the bus stop, or bleed more heavily than usual, they should see a doctor to check if they require iron supplements.
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