See your GP if you experience symptoms of iron deficiency anaemia. A blood test will be able to confirm the diagnosis. Your GP may also ask you a number of questions and carry out a physical examination to find out the cause of your anaemia.
To diagnose iron deficiency anaemia, a blood sample will be taken from a vein in your arm and a full blood count will be made. This means that all the different types of blood cells in the sample will be measured.
If you have iron deficiency anaemia:
- you will have lower levels of haemoglobin (a protein that transports oxygen) than normal
- you will have fewer red blood cells (cells that contain haemoglobin) than normal
- your red blood cells may be smaller and paler than usual
Your GP may also test for a substance called ferritin, a protein that stores iron. If your ferritin levels are low, you do not have much iron stored in your body and you may have iron deficiency anaemia.
Vitamin B12 and folate
If your GP suspects that your anaemia may be due to a vitamin B12 and folate deficiency, rather than an iron deficiency, your levels of these substances may be tested. Folate works with vitamin B12 to help your body produce red blood cells.
Vitamin B12 and folate deficiency anaemia is more common in people who are over 75 years of age.
See the Health A-Z topic about Vitamin B12 and folate deficiency anaemia for more information about this condition.
Finding the cause
To determine the underlying cause of your anaemia, your GP may ask you a number of questions about your lifestyle and medical history. For example, you may be asked questions about the following areas:
- your diet, to see what you typically eat and whether this includes any iron-rich foods
- any medicines that you take, to see whether you have been regularly taking a type of medicine that can cause gastrointestinal bleeding (bleeding from the stomach and intestines), such as ibuprofen or aspirin
- your menstrual pattern: if you are a woman, your GP may ask if you have been experiencing particularly heavy periods (menorrhagia)
- your family history: you will be asked whether any of your immediate family has anaemia or a history of gastrointestinal bleeding or blood disorders
- blood donation: your GP will want to know whether you regularly donate blood or if you have a history of excessive bleeding
- other medical conditions: your GP may ask whether you have recently had another illness or experienced any other symptoms, such as weight loss
Your GP may want to carry out a physical examination to try to confirm what is causing your iron deficiency anaemia. This will usually only be necessary if an obvious cause for your iron deficiency anaemia has not been found.
Your GP may:
- examine your abdomen (stomach) as gastrointestinal bleeding is a common cause of anaemia
- look for signs of heart failure (when your heart is not pumping blood around your body very efficiently), such as swollen ankles, as the main symptom of heart failure is extreme tiredness
Two other possible types of physical examination that you may have are explained below.
A rectal examination is a very common procedure. It can help your GP determine whether there is something in your gastrointestinal tract that may be causing bleeding. Your GP will insert a gloved, lubricated finger into your rectum so that they can feel for any abnormalities.
A rectal examination is not something to be embarrassed about as it is a procedure that your GP will be very used to performing. It should not cause you any significant pain or discomfort and you will only usually feel a slight sensation that your bowels are moving around.
Women may be advised to have a pelvic examination if their GP suspects that heavy menstrual bleeding (menorrhagia) may be the cause of their anaemia.
During a pelvic examination, your GP will examine your vulva and labia (external sex organs) for signs of bleeding or infection. They may also examine you internally. This will involve your GP inserting gloved, lubricated fingers into your vagina to feel whether your ovaries and uterus (womb) are tender or enlarged.
A pelvic examination will only be carried out by a healthcare professional who is qualified to perform the procedure, such as a GP or a gynaecologist (a specialist in the female reproductive system). A pelvic examination will not be carried out without your consent, and you will also have the option of having someone with you during the procedure.
As iron deficiency anaemia is common during pregnancy, if you have the condition while you are pregnant, your GP will not usually have to look for any other underlying causes.
Your GP will only look for an alternative cause if your haemoglobin level is particularly low, or if your symptoms or medical history suggest that your anaemia may be caused by other factors.
Your GP may refer you to a gastroenterologist (a specialist in treating conditions of the digestive system), who will be able to carry out a more thorough examination, if, for example:
- your GP detected an abnormality during a rectal examination
- you are anaemic and have experienced sudden or unexplained weight loss
- you are a woman who is not menstruating (having periods) and who has a very low haemoglobin level
It is very important to see a specialist if your GP recommends it. This will enable any more serious conditions to be diagnosed as soon as possible.
For example, in rare cases, gastrointestinal bleeding can be caused by cancer. The earlier gastrointestinal cancer is detected, the sooner it can be treated and the greater your chances of making a full recovery.
If you are a woman with heavy periods (menorrhagia), you may be referred to a gynaecologist if you fail to respond to treatment with iron supplements.