Anaemia (anemia): symptoms, causes, types and treatment

NHS inform says many people with iron deficiency anaemia only have a few symptoms, and that the severity depends largely on how quickly anaemia develops. You may notice symptoms immediately, or they may develop gradually if the anaemia is caused by a long-term problem such as a stomach ulcer.

The NHS lists the symptoms of iron deficiency anaemia in two groups. The less common ones are not usually connected to pregnancy.

The NHS explains that red blood cells carry oxygen around the body using a substance called haemoglobin, and that anaemia is the general term for having either fewer red blood cells than normal or an abnormally low amount of haemoglobin in each red blood cell. NHS inform adds that if you have fewer red blood cells than is normal, your organs and tissues will not get as much oxygen as they usually would.

There are several different types of anaemia, and each one has a different cause. NHS inform says iron deficiency anaemia is the most common type, and other types can be caused by a lack of vitamin B12 or folate in the body.

The two types most people meet in primary care are iron deficiency anaemia and vitamin B12 or folate deficiency anaemia. The NHS says the blood test used to check for iron deficiency anaemia also checks for other types.

The NHS says heavy periods and pregnancy are very common causes of iron deficiency anaemia, and that bleeding in the stomach and intestines is another common cause. This can be caused by taking non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen and aspirin, stomach ulcers, inflammation of the bowel or food pipe (oesophagus), piles, and, less commonly, cancers of the bowel or stomach.

NHS inform says that in men and post-menopausal women the most common cause is bleeding in the stomach and intestines. In women of reproductive age, heavy periods and pregnancy are the most common causes. Unless you are pregnant, it is rare for iron deficiency anaemia to be caused just by a lack of iron in your diet.

For vitamin B12 or folate deficiency, the NHS says pernicious anaemia, where the immune system attacks healthy cells in the stomach and stops the body absorbing vitamin B12, is the most common cause of B12 deficiency in the UK. A lack of these vitamins in the diet is uncommon but can happen with a vegan diet if you do not take B12 supplements or eat B12-fortified foods. Certain medicines, including anticonvulsants and proton pump inhibitors, can affect how much of these vitamins your body absorbs.

To check whether you have iron deficiency anaemia, the NHS says your GP will ask about your lifestyle and medical history and will usually do a blood test, a full blood count (FBC), to find out whether the number of red blood cells is normal. You do not need to prepare for this test.

If the reason for the anaemia is not clear, the NHS says the GP may do other tests, which might include a faecal immunochemical test (FIT) to look for blood in a sample of poo, or refer you to a specialist for further checks. The NHS says vitamin B12 or folate deficiency can often be diagnosed from symptoms and the results of a blood test.

Treatment depends on the cause. For iron deficiency anaemia the NHS says that once the reason has been found, such as an ulcer or heavy periods, the GP will recommend treatment. If the blood test shows your red blood cell count is low, iron tablets will be recommended to replace the iron that is missing, usually for about 6 months. Drinking orange juice after a tablet may help your body absorb the iron.

Some people get side effects from iron tablets, including constipation or diarrhoea, tummy pain, heartburn, feeling sick and darker than usual poo. The NHS suggests taking the tablets with or soon after food to reduce side effects and says it is important to keep taking them even if you get side effects. Your GP may repeat blood tests over the next few months to check that your iron level is getting back to normal. Keep iron tablets out of the reach of children; the NHS says an overdose of iron in a young child can be fatal.

For B12 deficiency anaemia the NHS says supplements are usually given by injection at first, then, depending on whether the deficiency is related to diet, as tablets between meals or regular injections. Treatment may last until levels have improved or for the rest of your life. Folic acid tablets are used to restore folate levels and usually need to be taken for 4 months.

If your diet is partly causing iron deficiency anaemia, the NHS says your GP will tell you which foods are rich in iron. NHS inform lists good sources of iron, and the NHS lists which foods and drinks can make absorbing iron harder.

• Iron-rich foods: dark-green leafy vegetables like watercress and curly kale, fortified cereals and bread, brown rice, pulses and beans, nuts and seeds, meat, fish and tofu, eggs and dried fruit such as apricots, prunes and raisins.

• Eat and drink less of tea, coffee, milk and dairy foods, and foods with high levels of phytic acid such as wholegrain cereals, in large amounts, because they can stop the body absorbing iron from other foods and tablets.

• Vitamin B12 is found in meat, fish, eggs, dairy products and specially fortified foods (NHS).

• Good sources of folate include green vegetables such as broccoli, brussels sprouts and peas (NHS).

• You might be referred to a specialist dietitian if you are finding it hard to include iron in your diet.

NHS inform says it is very common for women to develop iron deficiency during pregnancy because the body needs extra iron to ensure the baby has a sufficient blood supply and receives necessary oxygen and nutrients. Some pregnant women need an iron supplement, while others may only need to increase the iron in their diet.

A Hull University Teaching Hospitals NHS Trust leaflet explains that it is normal for blood levels to drop a little in pregnancy because there is more fluid in the blood to dilute the red blood cells, and that other causes include a diet low in iron, pregnancies close together and carrying twins or triplets. It says if you fail to respond to iron supplements, intravenous iron may be considered, and that iron supplements are better absorbed if taken an hour before meals, although taking them with or after food may reduce gut side effects.

The NHS says untreated iron deficiency anaemia can cause a greater risk of complications before and after birth if you are pregnant. NHS inform says that pregnant women with severe or untreated anaemia have a higher risk of complications. Talk to your midwife or GP.

The NHS says to keep iron supplement tablets out of the reach of children because an overdose of iron in a young child can be fatal. If you are worried that your child may be anaemic, see a GP, who can arrange a blood test. The NHS says a GP can usually diagnose iron deficiency anaemia with a full blood count.

The NHS says untreated iron deficiency anaemia can make you more at risk of illness and infection because a lack of iron affects the immune system, and may increase the risk of complications affecting the heart or lungs, such as an abnormally fast heartbeat (tachycardia) or heart failure.

For vitamin B12 or folate deficiency, the NHS says it is important to diagnose and treat as soon as possible because although many symptoms improve with treatment, some problems, such as those affecting the nervous system, can be irreversible. Adults with severe anaemia are also at risk of heart failure.

On the NHS, your GP can arrange a blood test and, if iron deficiency is found, look for the cause, which may include a referral for further tests. Treatment with iron, B12 or folic acid is usually started in primary care.

Private blood tests, including a full blood count, ferritin and B12 levels, are widely available. The results still need interpretation alongside your symptoms and history, and a cause should be looked for, so share the results with your GP.