Anaemia is not a disease in itself, but a result of malfunction somewhere in the body. This blood condition is common. Somewhere between approximately 1 in 60 to 1 in 80 people suffer from anaemia.
The following is an overview of this disorder so that, when your doctor informs you that you are suffering from ‘anaemia’, you will be in a position to know what your problem is, how you developed it and to be informed as to the correct approach to its management.
There are several definitions of ‘anaemia’. Anaemia is:
· a lack of blood in the body.
· a low proportion of red cells in the blood.
· a condition characterised by abnormally low levels of red blood cells or haemoglobin (the component of red blood cells that carries and delivers oxygen to tissues throughout the body).
· a deficiency in the number or quality of red blood cells.
· a condition in which there is a decrease in the quantity of haemoglobin or in the number of red cells.
· a pathological deficiency in the oxygen-carrying component of the blood measured in unit volume concentrations of haemoglobin, red blood cell volume or red cell number.
· a condition in which erythrocytes are reduced in number or volume or are deficient in haemoglobin.
Red Blood Cells and Haemoglobin
Red blood cells are called erythrocytes.
Red blood cells are formed in the bone marrow, and approximately 100 million new blood cells are formed daily. The raw materials required in the production of these cells are iron, proteins and vitamins, especially folic acid and B12. Of these, iron and proteins are essential in the formation of haemoglobin which gives the red blood cells their characteristic colour.
Red blood cells have a life span of about 120 days when they are then destroyed, the breakdown products returned to the bone marrow and new cells formed. This means that, every four months, the whole of the red cells in the blood are replaced.
Oxygen molecules attach themselves to haemoglobin, the content of the red blood cells, and hence they are carried to all parts of the body. The body’s cells need oxygen to live and perform their various duties. Oxygen is the nutrient most consumed by the body.
In general, there should be about 150 gm of haemoglobin per litre of blood. The range in health is 119-160 g/L.
Symptoms of Anaemia
Depending on the severity, the symptoms and signs of anaemia include:
· Pallor of the skin and mucous membranes
· Lack of energy, tiring easily
· Breathlessness, especially on exertion
· Poor memory
· Cracked or reddened tongue
· Dizziness and fainting
Diagnosis of Anaemia
Very few tests are needed to diagnose anaemia, the main one being a full blood count (FBC) – (see my September 2009 newsletter FBC, ESR, LFT, TSH – What Do These Mean?).
However, a complete history is essential. This should include reference to any chronic illness and regular medications that are taken.
An examination, by an experienced clinician, of nail beds and mucous membranes, especially the inner surface of the lower eyelid can give a remarkably accurate assessment of the presence or absence of significant anaemia.
The blood pathology tests not only include a FBC, but also blood iron levels, vitamin B12, folic acid and kidney function tests.
Urine tests should be carried out to detect the presence of blood in the urine.
Faecal occult blood test involves examining the stool for the presence of blood.
Gastroscopy and/or colonoscopy and possibly bone marrow biopsy may be necessary to determine the type of anaemia and its cause.
Causes of Anaemia
There are many causes of anaemia, but in all cases, red cells are lost more rapidly than they are replaced.
The three main classes of anaemia are:
1) excessive blood loss
2) excessive red blood cell destruction
3) deficient red blood cell production.
Causes of anaemia include:
· Blood loss. Due to trauma, surgery, cancer, peptic ulcer, heavy menstruation, bowel cancer, frequent blood donations, and drugs.
· Dietary deficiency. Lack of iron, vitamin B12 or folic acid in the diet. Starvation and malnutrition.
· Malabsorption. The body is not able to use the nutrients in the diet, caused by conditions such as celiac disease.
· Inherited disorders. These include thalassaemia and sickle cell disease.
· Autoimmune disorders. In autoimmune haemolytic anaemia, the immune cells attack the red blood cells and decrease their life span.
· Chronic diseases. These include rheumatoid arthritis and tuberculosis.
· Hormone disorders, such as hypothyroidism.
· Bone marrow disorders, such as cancer or infection.
· Drugs and medications. These include alcohol, antibiotics, anti-inflammatory drugs and anti-coagulant medications.
· Infection, especially malaria and septicaemia which reduce the life span of red blood cells.
· Periods of rapid growth or high energy requirements such as puberty or pregnancy.
TYPES OF ANAEMIA
1) Iron Deficiency Anaemia
The most common form of anaemia is iron deficiency anaemia, which basically means that the body is running low on iron.
The onset of iron deficiency anaemia is gradual and, at first, there may not be any symptoms. The deficiency begins when the body loses more iron than it derives from food and other sources. Because depleted iron stores cannot meet the red blood cells needs, fewer red blood cells are formed in the bone marrow. In this early stage of anaemia, the red blood cells look normal, but they are reduced in number. Then the body tries to compensate for the iron deficiency by producing more red blood cells, which are characteristically small in size. Symptoms are well established at this stage.
Iron deficiency anaemia is also called hypochromic (reduced haemoglobin and hence paler colour) anaemia and microcytic (small cells) anaemia.
2) Vitamin B12 Deficiency Anaemia
Vitamin B12 deficiency anaemia is also called pernicious anaemia. Unlike iron deficiency anaemia, where the cells are small, B12 deficiency anaemia has cells that are larger than normal cells, macrocytic or megaloblastic anaemia. There is also reduced haemoglobin, hence hypochromic anaemia. This anaemia develops when the body does not absorb enough B12 which is necessary for the creation of red blood cells. B12 is found in meat and vegetables.
Large amounts of B12 are stored in the body, so this condition may not become apparent until as much as four years after B12 absorption stops or slows down.
The B12 in the diet is called the extrinsic factor, and for its absorption it requires a substance secreted by the lining of the stomach, called the intrinsic factor. This intrinsic factor decreases with increasing age.
Pernicious anaemia is more common in older age. It also occurs in eating disorders or an unbalanced diet. A strict vegan diet is said to increase the risk of developing this condition, and many authors, especially those opposed to a vegan lifestyle, recommend B12 injections; such intervention is rarely required.
In the midst of the vast knowledge acquired during six years of medical school are some gems that are never forgotten. One such is the fact that a small tapeworm called diphyllobothrium latum can infect the gastrointestinal tract. This worm selectively consumes vitamin B12, and is thus one of the rare causes of pernicious anaemia.
Vitamin B12 is also essential for the normal functioning of the nervous system. Lack of B12 can lead to the development of inflammation of the nerves or dementia.
3) Folic Acid Deficiency Anaemia
Folic acid deficiency anaemia is the most common type of megaloblastic (large cells) anaemia, and is caused by a deficiency of folic acid, a vitamin that the body needs to produce normal cells.
This type of anaemia is common in infants and teenagers. Although this condition usually results from a dietary deficiency, it is sometimes due to an inability to absorb enough folic acid from foods such as cheese, eggs, fish, green vegetables, meat, milk mushrooms and yeast.
Vitamin C is essential for the absorption of folic acid.
Folic acid anaemia can be a complication of pregnancy.
4) Haemolytic Anaemia
Haemolytic anaemia is an autoimmune disorder where antibodies destroy red blood cells more rapidly than the bone marrow can replace them. The body produces auto-antibodies that coat the red blood cells. The coated cells are destroyed by the spleen, liver or bone marrow.
Haemolytic anaemia can enlarge the spleen, thus accelerating the destruction of red blood cells.
Thalassaemia is an inherited form of haemolytic anaemia. It stems from the body’s inability to manufacture as much normal haemoglobin as it needs.
There are two categories of thalassaemia, depending on which of the amino acid chains in the haemoglobin is affected. Haemoglobin is composed of four chains of amino acids. In alpha-thalassaemia, there is an imbalance in the production of the alpha chain, and in beta-thalassaemia, there is an imbalance in the beta chain. Alpha-thalassaemia most commonly affects black people, and beta-thalassaemias most commonly affects people of Mediterranean ancestry, and Southeast Asians.
Thalassaemia is characterised by the production of red blood cells that are usually small and fragile. It only occurs in those who inherit the gene for it from both parents.
6) Vitamin C Deficiency Anaemia
This is rare. In this type of anaemia, the lack of vitamin C causes the bone marrow to manufacture abnormally small red blood cells. The vitamin C deficiency results from severe long-standing dietary deficiency.
7) Sickle Cell Anaemia
Sickle cell anaemia is a chronic, incurable condition that causes the body to produce defective haemoglobin, which forces red blood cells to assume an abnormal crescent shape. Unlike normal oval cells, fragile sickle cells cannot hold enough haemoglobin to carry adequate amounts of oxygen to nourish body tissues. The deformed shape makes it hard for the sickle cells to pass through the capillaries, which may become obstructed, a life-threatening condition called sickle cell crisis.
Sickle cell anaemia is hereditary. It almost always affects only black people and people of Mediterranean descent.
8) Aplastic Anaemia
Aplastic anaemia is characterised by decreased production of red cells and also white cells and platelets. This disorder may be inherited, or acquired as a result of recent severe illness, long-term exposure to industrial chemicals, or the use of anticancer drugs and certain other medications.
It is sometimes curable by a bone marrow transplant, but it is a potentially fatal condition.
9) Anaemia of Chronic Disease
Cancer, chronic infection or inflammation, and kidney and liver disease often cause mild or moderate anaemia.
Treatment of Anaemia
The treatment will depend greatly on the cause of the anaemia. Treatments may include the following:
· vitamins and mineral supplements - in the case of deficiency
· iron injections - if the iron stores are very low
· vitamin B12, by injection - required for pernicious anaemia
· antibiotics - if infection is the cause
· altering the dose or regimen of regular medications - such as anti-inflammatory drugs
· blood transfusions - if required
· oxygen therapy - if required
· surgery to prevent abnormal bleeding - such as heavy menstruation, especially if this is due to fibroids
· surgery to remove the spleen (splenectomy) - in cases of haemolytic anaemia.
Iron deficiency anaemia is the most common type of anaemia. My April 2008 newsletter Iron addresses this important topic of iron in detail.
Early diagnosis is easy. A full blood count (FBC) measuring the number of red cells, looking at their characteristics such as size and shape, and the amount of haemoglobin will give the diagnosis. The cause must then be determined, and appropriately treated. Untreated anaemia will only get worse, with increasing severity of symptoms.
To diagnose anaemia early, and then find and identify the underlying cause and undertake the correct treatment could be life saving, for example the early diagnosis of colorectal cancer.
*Copyright 2010: The Huntly Centre.
Disclaimer: All material in the Huntlycentre.com.au website is provided for informational or educational purposes only. Consult a health professional regarding the applicability of any opinions or recommendations expressed herein, with respect to your symptoms or medical condition.
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