Anaemia

In our circulation red blood cells carry oxygen throughout our body, transporting oxygen in specialized proteins called haemoglobin. A decreased level of haemoglobin compared to normal is referred to as anaemia. This results in a reduced capacity for blood to provide organs with oxygen. In turn, the body needs to compensate for this by working harder in order to keep up with the same requirements such as increasing the breathing rate or heart rate.

At even lower levels of haemoglobin or when there is increased demand such as heavy exercise, normal function of organs cannot be achieved and injury to organs can develop.

The onset of the symptoms can vary in speed, depending on factors such as age, fitness and presence of other health problems, if any.

Red blood cells explained

Red blood cells are produced in the bone marrow. Once mature and released into circulation they have a life span of about 120 days. The bone marrow is always making new red blood cells to replace old ones which are cleared naturally. Millions of new red blood cells enter the blood stream each day in a healthy person.

Red blood cells contain proteins called haemoglobin. These proteins incorporate iron to bind oxygen. Red blood cells are transported through our circulation to our lungs where they receive oxygen, which in turn is released when they reach our organs in different parts of our body in order to supply them with oxygen for normal function.

The manufacture of red cells requires raw materials derived from our food, such as iron and vitamin B12. Our body is also able to recycle materials when cells are naturally broken down, to a certain extent. Iron is a major component in haemoglobin, critical for its oxygen binding ability.

Red cell production is regulated through the hormone erythropoietin, produced by kidneys, which stimulates bone marrow cells in manufacturing red cells.

Since the number of red cells and concentration of haemoglobin reflects the result of production and clearance or loss, anaemia itself is an abnormal state that can be caused by a variety of conditions. Loss or destruction of red cells overwhelming the capacity to replace them or decreased red cell production can both result in anaemia, but are distinct problems represented by a wide variety of conditions.

The discovery of anaemia should prompt further investigations as to the underlying causes. The treatment options depend on the reason causing anaemia.

Causes of anaemia

Anaemia can have many causes. Examples of these include:

• Dietary deficiency - Lack of iron, vitamin B12 or folic acid in the diet
• Malabsorption - Abnormalities reducing the body’s ability to absorb nutrients in diet, such as coeliac disease
• Inherited disorders- Genetic abnormalities involving abnormal haemoglobin production, such as thalassemia or sickle cell disease; or abnormalities in the enzymes involved in haemoglobin production, such as porphyria.
• Autoimmune disorders - Red cell life span decreased due to increased clearance by immune system such as autoimmune haemolytic anaemia or thyroid disease
• Kidney disease - Decreased erythropoietin production
• Chronic inflammatory diseases - Chronic inflammation such as seen in arthritis can result in reduced ability to utilize iron in the body
• Bone marrow disorders - Decrease production of red cells resulting from a malfunctioning bone marrow, such as in blood cancer
• Blood loss - Direct loss of blood such as in trauma, surgery, blood donation, menstrual periods, gastric ulcers, intestinal polyps
• Toxins or medications - Toxins such as alcohol can directly damage bone marrow; some medications can reduce bone marrow function
• Periods of increased need - Pregnancy
• Mechanical destruction - Mechanical heart valves can damage red cells reducing their natural life span
• Infections - Anaemia in infections are often due to several different mechanisms such as in malaria

Symptoms of anaemia

Depending on the severity, the symptoms of anaemia may include:

• Pale skin
• Fatigue
• Tiring easily
• Breathlessness
• Drop in blood pressure when standing from a sitting or lying position (orthostatic hypotension) – this may happen after acute blood loss, like a heavy period
• Frequent headaches
• Racing heart or palpitations
• Becoming irritated easily
• Concentration difficulties
• Cracked or reddened tongue
• Loss of appetite
• Strange food cravings.

Groups at high risk of anaemia

Certain people are at increased risk of anaemia, including:

• Menstruating women
• Pregnant and breastfeeding women
• Babies, especially if premature
• Children going through puberty
• People following a vegetarian or vegan diet
• People with cancer, stomach ulcers and some chronic diseases (particularly kidney disease & those on dialysis)
• People on fad diets
• Athletes.

Investigations in anaemia

Anaemia itself is demonstrated by doing a blood test measuring Full Blood Count (FBC) which will include Haemoglobin levels and red cell indices.

As the potential causes of anaemia are extremely varied, several other investigations are also needed. A thorough medical history and examination is required to elicit clues as to the underlying cause. Further specialized blood tests such as iron studies, hormone levels, kidney function might be required. More invasive tests such as endoscopy or bone marrow biopsy may need to be utilized in appropriate situations.

Treatment for anaemia

The treatment for anaemia is dependent on and should target the underlying problem. Causes of anaemia range from simple and mild to extremely severe and even life threatening.

If anaemia is due to more complex causes, other specialists such as haematologist or gastroenterologist may be involved in the management.

Treatment choice can also depend on the severity of anaemia or other factors influencing the health of someone with anaemia, such as age or the speed of development of anaemia.

Long-term outlook for people with anaemia

As the causes of anaemia a wide-ranging, prognosis of people with anaemia depends on the cause of their anaemia. For example, if the anaemia is caused by dietary deficiencies, correcting the cause and the use of appropriate supplements for some weeks or months will resolve the condition. Relapses may occur, so changes to diet and, perhaps, regular supplements may be necessary.

In other cases, the anaemia may be permanent and lifelong treatment is needed. No matter what the cause, it is important to have a doctor regularly monitor your blood to make sure your red blood cell and haemoglobin levels are adequate and to adjust treatment if required.

Prevention of anaemia

Some forms of anaemia can’t be prevented because they are caused by a breakdown in the cell-making process. Anaemia caused by dietary deficiency can be prevented by making sure that you eat food from certain food groups on a regular basis, including dairy foods, lean meats, nuts and legumes, fresh fruits and vegetables.

If you follow a vegan diet (one that does not include any animal products) talk to your health professional about recommended vitamin and mineral supplements.

If you have kidney disease, you should be tested for anaemia, 1 in 2 people with kidney disease will develop anaemia.

Where to get help

• Your GP (doctor)
• Dietitians Australia Tel. 1800 812 942
• Kidney Helpline Tel. 1800 454 363