This factsheet is for people who have anaemia caused by a lack of iron, or who would like information about it.
Anaemia is when there are too few red blood cells or not enough haemoglobin in the blood. The most common type of anaemia is iron-deficiency anaemia, caused when there isn't enough iron in the body.
About iron-deficiency anaemia
You need iron for many important processes inside your body, especially for making haemoglobin - the oxygen-carrying protein in your blood.
Iron is absorbed from your food and drink by your bowel. It's carried in your blood to your bone marrow, where blood cells are produced. Here, the iron is combined with proteins to make haemoglobin. Spare iron can be stored in your liver.
On average, men need 8.7mg of iron a day and women need 14.8mg a day. You can usually get all the iron you need from your diet.
Small amounts of iron are lost from your body in urine, faeces and dead skin cells. Much more is lost if you lose blood.
If you have a shortage, or deficiency, of iron in your body, your bone marrow will make small red blood cells that don't contain enough haemoglobin. These red blood cells can't carry enough oxygen to your organs and tissues. This leads to the symptoms of anaemia.
Certain groups of people are more likely to have iron-deficiency anaemia. These include babies, teenagers and women who have heavy periods.
Symptoms of iron-deficiency anaemia
The symptoms of iron-deficiency anaemia include:
- feeling breathless after little exercise
- feeling tired
- palpitations (the sensation of feeling the heartbeat thumping in the chest)
- looking pale
- a rapid pulse
Less common symptoms can include:
- tinnitus (ringing in your ears)
- an altered sense of taste
- brittle nails or 'spoon nails' where the middles of your nails are pushed inwards and the edges are raised
- soreness at the edges of your mouth
- a short attention span and poor concentration
These symptoms aren't always due to iron-deficiency anaemia but if you have them, see your GP.
Complications of iron-deficiency anaemia
If iron-deficiency anaemia isn't treated, there are a range of possible complications. For example in adults, it can affect your ability to work and exercise. It can also increase your risk of heart problems. Ask your GP for more information.
Causes of iron-deficiency anaemia
Loss of blood
Iron-deficiency anaemia is usually caused by heavy bleeding, such as from an injury or after an operation. A common cause of iron-deficiency anaemia in women is bleeding from heavy periods.
You're more likely to develop iron-deficiency anaemia if you:
- take aspirin or other non-steroidal anti-inflammatory drugs (NSAIDs) as these can cause stomach bleeding
- have problems with your digestive system that may lead to bleeding in your stomach or bowel
Diet and digestion
You may develop an iron-deficiency anaemia if you don't get enough iron in your diet, or if the iron in your diet isn't absorbed properly.
A healthy diet including meat contains enough iron for most adults. Red meat is the richest source of iron and the iron is easily absorbed by your body. If you follow a vegetarian or vegan diet, you may not be able to get enough iron. This is because, although you can get iron from foods such as pulses, green leafy vegetables and nuts, the iron in these foods isn't absorbed so easily.
Conditions that affect your digestive system can cause iron-deficiency anaemia. For example, coeliac disease damages the lining of your small bowel and prevents the normal absorption of nutrients, including iron. If you have surgery on your stomach or small bowel, this can also affect your absorption of iron.
It's very common for women to develop iron-deficiency anaemia during pregnancy because their unborn baby needs iron and takes its supply from its mother. Iron deficiency is more likely to develop during pregnancy in women whose diet doesn't contain plenty of iron.
Children and toddlers may develop iron-deficiency anaemia because growth spurts take up extra iron.
Occasionally, in women over 40, iron deficiency is part of a condition called Plummer Vinson syndrome. This condition makes it difficult for you to swallow as it causes small web-like growths to develop in your oesophagus (the pipe that goes from your mouth to your stomach).
Diagnosis of iron-deficiency anaemia
Your GP will ask about your symptoms and examine you. He or she may also ask you about your medical history.
Your GP will ask you to have a blood test. Your blood sample will be sent to a laboratory for testing, including a full blood count (FBC) to give information about your haemoglobin level and how many of each of the different types of blood cells you have. A FBC also gives information about the size of your red cells and the amount of haemoglobin each one contains.
The normal amount - or concentration - of haemoglobin is:
- at least 13g/dl (13 grams of haemoglobin per decilitre of blood - a decilitre is 100ml) for men
- at least 11.5g/dl for women
- at least 11g/dl for pregnant women
The values for children vary by age - ask your GP for more advice.
If your haemoglobin level is low, and your red cells are small, you may have iron-deficiency anaemia. You may need to have other blood tests, such as a ferritin test, which can give an idea of how much iron is in your body.
Depending on the suspected cause of iron-deficiency anaemia, your GP may refer you to one of the following doctors for further tests.
- A haematologist (a doctor who specialises in treating blood disorders).
- A gastroenterologist (a doctor who specialises in conditions of the digestive system).
- A gynaecologist (a doctor who specialises in women's reproductive health).
Treatment of iron-deficiency anaemia
Your doctor will first try to identify why you're deficient in iron so that the cause can be treated.
You may need to improve your diet so that it includes more iron. Your doctor may refer you to a dietitian for advice on how to do this.
Your doctor may prescribe iron supplements, such as ferrous sulphate tablets. Iron supplements make up for the shortage of iron and will then build up your body's stores of iron to the normal level. You will usually need to take tablets two to three times a day for up to seven months. Always read the patient information leaflet that comes with your medicine and ask your GP or pharmacist for advice if you have any questions.
Iron supplements can have side-effects. These include feeling sick, heartburn, constipation and diarrhoea. They can also cause your faeces to turn black. These side-effects may be reduced if you take the tablets after meals.
If you have another problem, such as blood loss, you may need treatment for this as well as a course of iron tablets.
Prevention of iron-deficiency anaemia
You can reduce your risk of developing iron-deficiency anaemia by eating a healthy, balanced diet that contains plenty of iron.
Good sources of iron include:
- meat (of course not this if you are vegetarian)
- green vegetables
- dried fruit
- pulses, such as chick peas and lentils
- foods that are fortified with iron, such as some breakfast cereals and bread (fortified means that iron has been added during manufacturing)
It's thought that vitamin C might help you to absorb iron, so if you have a glass of orange juice with your meal it may help to improve your levels of iron. You could also eat foods containing vitamin C at the same time as eating foods containing iron. Good sources of vitamin C include peppers, sweet potatoes, oranges and kiwi fruit.
What you drink affects how your body will absorb iron. Tea and coffee contain substances called polyphenols that can bind with iron and make it harder for your body to absorb it. If you cut down on the amount of tea and coffee it could help to improve iron levels in your body.
Iron is stored in your body and too much iron can be harmful. Only take iron supplements if your doctor recommends it.