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Anaemia
is a condition in which the blood cannot carry enough oxygen,
either because there is a low number of red blood cells or
because each red blood cell is able to carry less oxygen than
normal. There are many different types of anaemia with
different causes. Iron deficiency is a common cause.
Symptoms of anaemia include feeling tired or faint and getting
breathless easily. Treatment usually involves taking iron
tablets and treating the underlying cause.
About blood
Blood is made up of fluid
called plasma which contains three types of cells:
- white blood cells – these are part of the immune system,
the body’s defence against infection
- platelets - these are involved in blood clotting
- red blood cells - these carry oxygen around the body in
a pigment called haemoglobin
Red blood cells are made by the body in the bone marrow and
live for around four months before they are destroyed and
replaced, as part of a normal renewal process.
Anaemia
due to iron deficiency
Anaemia
is a condition in which the blood cannot carry enough oxygen.
This may be because there are less red blood cells than
normal, or because there is not enough haemoglobin in each
cell.
Iron is the main component of haemoglobin. Lack of dietary
iron is the world's leading nutritional deficiency and the
most common cause of anaemia.
Other vitamins that are needed for the body to make red
blood cells include folate (folic acid) and vitamin B12. A
lack of these in the diet can cause anaemia. For more
information about these, please see the separate BUPA
factsheets on Folate-deficiency anaemia and Vitamin
B12-deficiency anaemia.
Causes of iron-deficiency
anaemia
- A common cause of
iron-deficiency anaemia in women is heavy periods (menorrhagia).
About 1 in 10 women become anaemic at some time in their
life due to heavy periods.
- Stomach ulcers, piles, ulcerative colitis (inflammation
of the colon) and bowel cancer may cause bleeding in the gut
and result in anaemia. Often the bleeding is not obvious
because the blood is passed unnoticed in the stools.
- Kidney or bladder disease can cause bleeding that can
result in anaemia. The blood may be passed unnoticed in the
urine.
- Some bowel conditions, such as coeliac disease (gluten
sensitivity) or chronic diarrhoea, cause poor absorption of
foods containing iron.
- Low dietary iron can lead to anaemia, although there are
many sources of iron, including meat, green vegetables,
milk, flour and eggs. In the UK, a lack of iron in the diet
is unlikely to be the cause of anaemia, except in very young
children.
- Pregnancy can lead to iron-deficiency anaemia, because
the growing baby needs iron and takes its supply from the
mother. Iron deficiency is more likely to develop during
pregnancy in women whose diet does not contain plenty of
iron.
- Certain medical conditions, such as rheumatoid arthritis
or cancer, can lead to iron-deficiency anaemia. In this case
adequate iron is present in the diet, but the developing red
blood cells in the bone marrow cannot use the iron properly.
- Long-term aspirin-taking is associated with
iron-deficiency anaemia because it can cause bleeding in the
stomach without any symptoms.
- Hookworm infection can cause iron-deficiency anaemia,
and is the most common cause worldwide. People who live in
or travel to tropical countries are at risk of hookworm
infection. Hookworms feed off blood inside the intestines.
Symptoms
People with iron-deficiency
anaemia have symptoms caused by a low level of oxygen in the
blood. These include:
- breathlessness
- tiredness
- dizziness
- rapid, weak pulse or palpitations
- headaches
Less common symptoms can include tinnitus (ringing in the
ears) and altered taste.
As well as having the symptoms of anaemia, people with iron
deficiency may have pale skin, brittle nails, cracked lips and
an inflamed tongue. Very rarely, people get pica, which is a
craving for non-food substances such as ice.
Occasionally, in women over 40, iron deficiency can be a
symptom of a condition called Plummer-Vinson syndrome. This
also causes swallowing difficulties and occasionally web-like
growths in the oesophagus.
Iron deficiency can also reduce attention span, cause
behavioural and developmental problems in young children and
weaken the immune system.
Diagnosis
Anyone with symptoms that may
be due to anaemia, such as paleness, weakness and fatigue,
should visit their GP. He or she will ask about your symptoms,
medical history and current eating habits, and may perform a
physical examination.
A simple blood test can measure the number of red cells and
the amount of haemoglobin in the blood. The normal amount is
at least 13g/dl (13 grams of haemoglobin per decilitre of
blood) for men and 11g/dl for women. This test can determine
if you are anaemic, but does not identify the cause of the
anaemia.
Sometimes the cause is clear, for example in women who are
pregnant or have heavy periods. However, if the cause is not
clear, the GP may recommend further tests.
These may include investigations into possible bleeding in
the gut, such as a colonoscopy. A colonoscopy is an
examination of the lining of the colon (large bowel) using a
flexible, tube-like telescope called a colonoscope. This
instrument is carefully passed through your back passage and
into the colon. A biopsy (small sample of tissue) may be taken
from the lining of the gut.
Another way of examining the gut is a barium enema. Barium
shows up on X-rays. For the test, a fluid containing barium
dye is inserted into the back passage. An X-ray is then taken
and the bowel can be seen.
Anyone who has recently been to a tropical country may have
a test for hookworm.
Treatment
Treatment depends on the cause
of anaemia. For many people the treatment is iron tablets. The
length of treatment with iron depends on how severe the
anaemia is. The blood may be tested after a few weeks to check
that the level of haemoglobin is returning to normal. Once the
haemoglobin level is back to normal, iron supplements may
still be advised for another three months. A diet high in iron
will also be recommended.
Anyone who has difficulty absorbing iron may need iron
injections instead of tablets.
Iron supplements can have side-effects. These include
constipation, diarrhoea, an upset stomach or feeling sick. The
stools may also turn black.
If there is an underlying cause, such as bleeding, this
needs to be treated.
Prevention
The best way to prevent
iron-deficiency anaemia is to eat a diet containing plenty of
iron. The recommended daily amount is 7mg a day for men and
11mg a day for women. Iron is found in meat, liver, cereals,
raw green vegetables, fortified foods such as some breakfast
cereals.
It's a good idea to eat foods containing vitamin C at the
same time as eating non-meat sources of iron because this
helps with iron absorption. Good sources of vitamin C include
peppers, Brussels sprouts, sweet potatoes, oranges and kiwi
fruit.
Women who have heavy periods should consider taking an iron
supplement. Speak to your GP or contact a dietician for more
information.
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