I am currently reading a book called The Anarchy by William Dalrymple, a book detailing a state of anarchy existing in India in the eighteenth century which made it easy for the British East India company to defeat the ruling Kings and take over the country. Apparently at the time when Lord Cornwallis ran the EIC, Britain had lost its American colonies to the descendants of the original european settlers (and not the locals). In India, one in three British men were “cohabiting” with Indian women and it was believed that there were 11000 Anglo-Indians living in the 3 Presidency towns ( Madras, Calcutta and Bombay). Fearful of losing their Indian territories in the future to the descendants of British men, the EIC banned all Anglo-Indians “orphans” from serving in the company army (as well as in the civil and marine branches of the EIC) and from owning land thereby excluding them from most lucrative sources of employment. They were only allowed to work as pipers, drummers and farriers in the company army and were further demoted to holding minor jobs as clerks, postmen and train drivers. The Anglo- Indian community was therefore relegated to the fringes of Indian society where they developed their own unique culture and spoke English in their own unique style. My father had told me many years ago that “bloody” and “bugger” were words used primarily by the Anglo-Indian communtiy and that it subsequently become common usage. I remember using these words without knowing their meaning as a child, at home in front of my parents and never being corrected or admonished. So kindly excuse my use of those words in this article.
So, this article is written to give you more information of the common causes for anaemia, why they happen and give you some information as to what you can do about it. I write this article from my perspective and experience as a doctor practising in an urban setting in South India.
Low hemoglobin in referred to as Anaemia. Men are anaemic if their hemoglobin in less than 13.6 gm/dl (hematocrit <41%) and in women if hemoglobin is less than 12gm/dl (hematocrit <36%). Worldover, the commonest cause for anemia is Iron deficiency.
Hemoglobin serves the very important function of carrying Oxygen to all the tissues. Oxygen is picked up in the lungs and delivered to the tissues in every corner of the body. Therefore when anemic, the person may feel breathless on exertion (or even at rest when severe), tired, dizzy with chest pain, cold extremities and pallor. The person could also be absolutely asymptomatic especially if the anemia develops gradually over several months or years.
The cause of the anemia could vary according to the age at detection. In children, Nutritional Iron, B12 and folate deficiency, Hook worm infestation, Hemolysis and heriditary causes (Thalassemia or Sickle cell anemia) may occur.
In adults, Iron deficiency due to Acute or chronic blood loss (menstrual blood loss, Gastrointestinal bleeding from piles, stomach ulcers etc worsened by antiplatelet drugs such as Aspirin or Clopidogrel), Kidney failure, chronic diseases and Cancer chemotherapy.
In the elderly, anemia can be caused by Chronic diseases, Iron deficiency (from gastrointestinal blood loss), Vit B12/Folate deficiency, Chronic leukaemia and cancers, Myelodysplastic disorders and blood loss (acute from fractures after falls and chronic from intestinal bleeding).
Broadly Anaemia can be divided into the following categories:
Reduced production of blood
Deficiency Anaemia – Iron, B12 and Folate.
Bone marrow disease – Acute and Chronic leukaemia, lymphomas and other bone marrow malignancies, Aplastic anaemia, Myelodysplastic syndrome, Myelofibrosis and Infections affecting the bone marrow.
All blood cells are produced in the bone marrow and any disease that affects the bone marrow can cause anaemia.
Anaemia of Chronic disease – Chronic disease such as Inflammatory bowel disease, Rheumatoid arthritis affect the transfer of iron from the immune cells to the bone marrow.
Anaemia of Kidney failure – the kidneys produce Erythropoietin, a hormone that stimulates the bone marrow to produce blood. When this stimulus reduces due to kidney failure,anaemia ensues.
Increased Blood destruction or loss
Blood loss – acute and chronic.
Hemolytic – Heriditary (Hemoglobinopathies), Autoimmune, Enzyme defects(G6PD), MAHA
Overactive spleen (Hypersplenism)
So how do you go about finding out the cause for your anaemia?
The following tests would be useful.
The CBC – complete blood count
Hemoglobin levels – based on the hemoglobin levels anaemia can be classifed as mild (>10gm/dl) moderate (7-10gm/dl) and severe ( <7gm/dl).
MCV – mean corpuscular volume
– A low MCV occurs frequently in Iron deficiency and a high value >100 in Vit B12 and folate deficiency.
Platelet counts – are reduced in acute infections and Vit B12 and folate deficiency and Bone marrow disease. A high platelet count is seen in Acute as well as chronic blood loss.
ESR – increases in all Anaemias.
CRP – increases in all inflammatory and infective conditions.
Reticulocyte count and index – A normal or increased Reticulocyte count and index indicates a functioning bone marrow and could indicate blood loss or hemolysis as a cause for the anaemia.
Peripheral smear – especially reported by a human rather than an automated machine will give a very valuable information regarding the cause for anaemia.
Iron study – Serum Iron, Transferrin saturation and Ferritin – Low serum iron, low transferrin saturation (low TIBC) and a low Ferritin indicate iron deficiency. A normal or high iron, normal or low saturation and a high Ferritin level would indicate Chronic infection and inflammation.
Serum LDH – lactate dehydrogenase – rises in hemolytic anaemias and other hematoloic conditions.
Stool for occult blood – positive report would indicate gastrointestinal blood loss.
Serum Vit B12 and folate levels – are reduced in Megaloblastic (macrocytic) anaemia due to B12 and folate deficiencies.
Renal function test – Urea and creatinine – Creatinine levels > 4 mg/dl may indicate a renal cause for Anaemia.
Haemoglobin electrophoresis – can help diagnose Thalassaemias.
Bone marrow aspiration and biopsy study – Will indicate if an underactive bone marrow is the cause for the anaemia.
Osmotic fragility – Increases in Heriditary spherocytosis.
Coombs test – is positive in Autoimmune Hemolytic anaemias.
Case studies: Lets have a look at a few case stories from my practice.
1. Mrs. M was a 38 yr old lady who was seen by her gynaecologist for anemia and was prescribed iron tablets as emperic treatment of Iron deficiency anemia due to menstrual blood loss.I had seen her a month later for severe abdominal pain and constipation.As her stool occult blood test returned positive, a colonscopy was done and it showed a large growth nearly occluding the rectal lumen (and she had been absolutely asymptomatic till then).She underwent surgery to relieve obstruction and later succumbed to the cancer despite best therapy.
Moral of the story- every case of suspected anaemia needs relevant investigations!
2. Mr. A was a 21 yr old man studying in Canada. He was my patient since the age of 16yr and his parents were always unhappy that he was a poor eater and liked only junk food like pizzas and bread! He was brought to my clinic by his father who was concerned that his son looked weak, the blood tests done revealed anemia which was thought to be due to iron deficiency as it was of the microcytic type.I ran a set of tests on him which showed that his iron levels were normal. A Hemoglobin electrophoresis test done revealed Thalassaemia minor. In this case giving iron tablets would have been the wrong thing to do.
Moral of the story- every case of anemia needs relevant investigations!
3. Mr.S was a 36 yr old patient of chronic deforming Rheumatoid arthritis. He gave a history of previous blood transfusions for anaemia and of regular intake of pain killing tablets for his joint pains. His Hemoglobin was 3.5gm/dl, ESR and CRP were very elevated, the iron study revealed low iron and elevated ferritin levels and the stool occult blood test was negative. He was diagnosed to have anemia of chronic disease. He was transfused to hemoglobin of 8gm and was started on DMARDS for his Rheumatoid arthritis.
Moral of the story – not every case of anemia is due to Iron deficiency.
4. Mr. H was a reformed alcoholic who came with complaints of weakness and tiredness. His examination revealed signs of chronic alcoholic liver disease with ascites (abdominal swelling due to fluid collection). Investigations revealed moderate anemia with hemoglobin of 8gm/dl, pancytopaenia (reduction of Red cells i.e., anaemia, white cells and platelets) and fecal occult blood test was positive. He was diagnosed to have anemia due to hypersplenism and due to GI blood loss. The patient was transfused to a hemoglobin of 10gm/dl, his coagulation disorder was corrected and he had a endoscopic procedure to treat his bleeding varices.
Moral of the story – your doctor can find clues to the cause of anemia. So if you are anemic, go see your doctor and get it corrected.
5. Mr. N came to see me with some dyspeptic symptoms. His hemoglobin was 8gm/dl and his MCV was 105. His peripheral smear showed macrocytic anaemia suggestive of megaloblastic anemia with hypersegmented nuclei on Neutrophils. He tested postive for anti Intrinsic factor antibodies, his vit B12 levels were very low and an endoscopy done revealed atrophic gastritis. He was diagnosed to have Pernicious anemia due to Vit B12 deficiency and was given IM injections of Vit B12 after which his hemoglobin returned to normal.
Take home message: If you are anaemic, get some tests done, see your doctor before you start giving any excuses to explain why you are anemic.