You will probably begin by seeing your GP (family doctor) who will examine your breasts. If your GP thinks that cancer may be present, or is not sure what the problem is, you will be referred to hospital for specialist advice or treatment.

At the hospital the doctor will take your medical history before carrying out a physical examination. They will examine your breasts and feel for any enlarged lymph glands under your arms and at the base of your neck.

The following tests may be used to diagnose breast cancer. You may have one or two of the tests, or a combination. It can be helpful to have a friend or relative with you when you go for any tests or to get your results:

A mammogram is a low-dose x-ray of the breast tissue. You will need to take off the clothes from the top part of your body, including your bra. The radiographer will then position you so that the breast is against the x-ray machine and gently but firmly compressed with a flat, clear, plastic plate. Two mammograms (from different angles) are taken of each breast.

The breast tissue needs to be squashed to keep the breast still and to get a clear picture. Most women find this uncomfortable and for some women it is painful for a short time. You will need to stay still for less than a minute while the picture is taken.

Mammograms are usually used for women over the age of 35. In younger women the breast tissue is more dense, which can make it difficult to detect any changes on the mammogram.

An ultrasound uses sound waves to build up a picture of the breast tissue. Ultrasound can often tell whether a lump is solid (made of cells) or is a fluid-filled cyst. It can also often tell whether a solid lump is likely to be benign or malignant.

You will be asked to take off the clothes from the upper part of your body and lie down on a couch. An ultrasound specialist will then put gel onto the breast and gently rub a small microphone-like device over the affected area. This shows a picture of the internal tissue of the breast on a screen. Ultrasound is painless and only takes a few minutes.

A colour Doppler ultrasound machine can show the blood supply to the lump. The blood supply shows up as patches of red or blue colour on the scan and the pattern of the blood flow can help to tell the difference between a cancer and a benign lump.

A needle (core) biopsy may be done. A doctor uses a needle to take a small piece of tissue from the lump or abnormal area. Local anaesthetic is injected into the area first to numb it. You may feel a little soreness or a sensation of pressure for a short time. Several biopsies are usually taken at the same time.

The sample is then sent to a laboratory to be looked at by a doctor who is expert at diagnosing illness by looking at cells (a pathologist). Depending on the number of biopsies taken, the breast tissue may be quite bruised and sore afterwards, and this may take a couple of weeks to completely disappear.

A fine needle aspiration (FNA) is a quick, simple procedure which is done in the outpatient clinic. Using a fine needle and syringe, the doctor takes a sample of cells from the breast lump and sends it to the laboratory to see if any cancer cells are present. As the breast is sensitive, the needle aspiration may be quite uncomfortable and the breast may be bruised for a week or so afterwards.

Sometimes (especially if the lump is small) a needle aspiration may be carried out in the x-ray department. The doctor uses x-ray or ultrasound guidance to make sure that the needle takes cells from the abnormal area of the breast.

Samples of your blood will be taken to check your general health, the number of cells in your blood (blood count) and to see how well your kidneys and liver are working. Your blood may also be tested to see whether it contains particular chemicals (markers), which are sometimes produced by cancer cells.

An excision biopsy may be done. The whole lump is removed under a general or local anaesthetic and sent to a laboratory for examination under a microscope. This may mean an overnight stay in hospital but is done as day surgery in some hospitals.

If a lump is too small to be felt, but has shown up on mammography or ultrasound, the radiologist may need to mark the area for the surgeon, before the excision biopsy. This is done by inserting a very small wire (a guide wire) under local anaesthetic, using x-ray or ultrasound guidance. The procedure is known as wire localisation.

Many hospitals have a special 'one stop' breast cancer clinic. This means you will have all the necessary tests and some of the test results on the same day. In other hospitals it may take longer for the results to come through.

This waiting period can be an anxious time for you and it may help to talk about your worries with a partner, close friend, relative, breast care nurse, counsellor or one of the organisations we list.