Anaemia is relatively common and if untreated can cause serious problems, but once diagnosed it is generally easily remedied. Robert Mair explains the types, symptoms, how it's diagnosed and most common treatments.

In this article:

What is anaemia?

What is anaemia?

Anaemia is a condition that occurs when there are a reduced number of red blood cells or haemoglobin concentration in the blood.

There are two main types of anaemia: iron deficiency and pernicious.

Iron deficiency anaemia is the most common type of anaemia. This is where the body lacks enough iron to keep the red blood cells functioning properly. Iron is a key component of haemoglobin, which stores and carries oxygen in blood cells. Without enough iron, blood cells carry less oxygen to the body’s tissues and organs. 

Iron deficiency anaemia is caused by:

  • Lack of iron in the diet. Iron is found in meat, dried fruit and some vegetables e.g. spinach
  • Poor absorption of iron. Some conditions, such as coeliac disease, can adversely affect iron absorption
  • Menstruation. Usually only in women who experience particularly heavy periods
  • Pregnancy. Expectant mothers commonly develop anaemia because the body needs extra iron so the baby has sufficient blood supply and receives all the necessary oxygen and nutrients
  • Stomach or intestinal bleeding. This can occur in men and post-menopausal women and is brought about by: prolonged use of non-steroidal anti-inflammatory drugs, such as aspirin or ibuprofen; stomach ulcers or stomach cancer 

Pernicious anaemia is caused by a deficiency of vitamin B12, which is vital for cells in the body to multiply. Where there is a lack of vitamin B12 red blood cells are produced in smaller numbers, are abnormally large in size and don’t last as long as they should.

Commonly, pernicious anaemia is caused by the body’s inability to absorb vitamin B12 properly because of a lack of a substance called intrinsic factor. This is made in the stomach, but if the cells that do this are damaged, possibly because of an ulcer, cancer or bowel surgery, vitamin B12 is no longer absorbed and a deficiency develops.

In some cases pernicious anaemia stems from a lack of vitamin B12 in the diet. Vitamin B12 is found in foods such as meat, fish, cheese, eggs and milk, so strict vegetarians or vegans can be prone to pernicious anaemia if they don’t take vitamin supplements.

Pernicious anaemia is most common in older people, affecting about 1 in 8,000 people over the age of 60. It is more common in women than men.

It tends to run in families and is more likely to occur if a relative already has a thyroid gland problem. 


Pernicious and iron deficiency anaemia have several symptoms in common, including: 

  • Tiredness and lethargy (lack of energy)
  • Heart palpitations
  • Weight loss
  • Pale complexion

Other symptoms of iron deficiency anaemia include: 

  • Altered sense of taste
  • Difficulty swallowing
  • Ulcers in the corners of the mouth
  • Dry, flaky nails

Other symptoms of pernicious anaemia include:

  • Inflammation of the nerves
  • Problems with coordination
  • Irritability
  • Depression

Without treatment, prolonged iron deficiency anaemia can cause hair loss, increase the risk of heart failure and lower the body’s immune system. In severe cases, it’s possible it may increase the risk of developing an abnormally fast heartbeat (known as tachycardia). At its most extreme iron deficiency has caused heart failure.

Meanwhile, sustained pernicious anaemia can affect the nervous system and lead to problems with vision or memory. It can also lead to temporary infertility and increase the risk of cardiovascular disease.


In both cases, a blood test at your local surgery can determine whether someone has anaemia.

For pernicious anaemia, the Schilling test measures the body’s ability to absorb vitamin B12 from the bowel. This shows whether the anaemia is caused by a lack of intrinsic factor.

With iron deficiency, the blood test measures the amount of haemoglobin and the number of red blood cells in the blood.

In addition, the GP may undertake a physical examination to determine whether there is an underlying cause of the anaemia. This can involve a rectal examination to search for any abnormalities. For women, a pelvic examination may be conducted if it is suspected that heavy menstrual bleeding is the cause of their anaemia.

If any abnormalities are found the patient may be referred to a gastrointestinal specialist, who will carry out a more thorough examination.


Fortunately, anaemia itself is easily treated – although any underlying cause will have to be separately dealt with.

Generally, for pernicious anaemia, an injection of vitamin B12 is administered: it is not absorbed properly if taken orally.

Once the deficiency has been treated, patients will probably need a maintenance dose of vitamin B12 every three months for the rest of their lives.

In cases of iron deficiency anaemia, a course of iron tablets lasting several weeks should bring iron levels back to normal. The tablets should be taken for a further three months after iron levels return to normal to ensure reserves are built up.

If a lack of iron in the diet is a cause, the patient may be recommended to eat more food that is high in iron, such as: green, leafy vegetables, beans, meat, dried nuts, prunes and apricots.

Some foods, drinks, specific minerals and medicines can impact your body’s ability to absorb iron. These include:

  • Tea and coffee
  • Indigestion remedies (known as antacids)
  • Calicum, found in dairy products such as milk