Facts about anaemia

By Brigid Monda

Our blood is a thickish red fluid pumped around the body by the heart. The average adult has six to eight litres of it. Blood is life — it feeds every cell in the body, gets rid of all the waste products, protects the body from infection and repairs any damage the body may sustain. Without it, we cannot survive. Blood is made up of two main components: Plasma, the liquid part and a large number of different types of cells that are suspended in the plasma. The plasma acts as their means of transport to all the corners of the body where they perform different functions. One group of these cells is the red blood cells that contain a red pigment called haemoglobin — which is responsible for the colour of blood. The main function of red blood cells is to transport oxygen and carbon dioxide to other parts of the body.

The oxygen that we breathe in is absorbed through our lungs into the blood and then carried to all the other cells in the body by the haemoglobin. The red blood cells are active mini factories that work day and night to keep us alive and they need oxygen to perform their tasks and in the production of energy as the body ‘burns fuel’ mainly in the form of glucose. These little factories produce waste products like carbon dioxide, which has to be disposed of before it accumulates and poisons the entire body. Hence, it is carried back to the lungs by the haemoglobin where it is breathed out from the body.

When your haemoglobin level is below what is considered normal for your age and sex, you are then said to be suffering from anaemia.

Symptoms of anaemia

The inadequate levels of haemoglobin translate into a decreased oxygen carrying capacity of the blood and a decreased supply of oxygen to the tissues causes the typical symptoms of anaemia. A person becomes pale as levels of redness of the blood decrease and because blood is shunted from the peripheral organs like the skin to the more essential ones like the brain and kidneys. This causes the affected person to become hypersensitive to cold; they get dizzy and have headaches because the brain does not get adequate supply of oxygen. They get palpitations because the heart pumps faster than normal to get this blood with its low oxygen content to the vital organs of the body. And in severe cases, the heart will fail.

Anaemia also lowers resistance to infection by weakening the immune system. It also has a very negative effect on the outcome of a pregnancy because the baby in the womb is completely dependant on the mother for everything. It cannot breathe, feed or get rid of any waste products on its own. It is the mother’s blood that carries out all these important jobs for the baby. It carries oxygen and food to the baby and carries away its waste products for disposal through the mother’s waste disposal system.

Types of anaemia

There are different types of anaemia with as many different causes.

Iron deficiency anaemia: It is the most common and affects women mainly. Iron is required for the manufacture of haemoglobin and a lack of it will cause this type of anaemia. Common causes of iron deficiency anaemia include: An iron deficient diet, poor iron absorption in certain intestinal diseases, hookworm infection because they feed on blood and cause bleeding from their feeding sites, malaria, heavy menstrual bleeding, depletion of iron stores due to poorly spaced pregnancies and blood loss through internal bleeding from peptic ulcers or piles.

Vitamin B12 deficiency anaemia: It is caused by a lack of vitamin B12, which is also essential for the formation of haemoglobin. It may be due to a deficient diet particularly in vegetarians, disease of the small intestine causing poor absorption of the vitamin like in Crohn’s or Coeliac disease or if a person’s stomach does not secrete enough of a special factor that enables the vitamin to be absorbed.

Renal anaemia: It results from kidney disease — which is also another important cause of anaemia, and in particular, Chronic Kidney Disease (CKD). Kidney disease interferes with the production of red blood cells because the kidneys play a very important role in their production.

The kidneys have specialised cells that secrete the hormone erythropoietin, which stimulates the production of red blood cells in the bone marrow. These specialised cells are sensitive to low oxygen levels in the blood, in which case they release erythropoietin. Erythropoietin in turn stimulates the bone marrow to produce more red blood cells thereby increasing the oxygen-carrying capacity of the blood. Erythropoietin is actually the prime regulator of red blood cell production in the body so if the kidneys are not functioning at optimum or as their function declines, renal anaemia develops and leads to complications from the anaemia like heart failure and even death if untreated.