Diagnosing cancer

Usually your doctor will refer you for tests to find out what is causing a particular symptom.

The tests will depend on which type of cancer is suspected. Common tests to diagnose cancer are:

Scans, such as MRI scans, X-rays and ultrasound scans: These can sometimes show a mass inside your body, which could be a tumour.
Scopes: Scopes are tubes put into your body with a light and a camera on the end. Scopes let your doctor see inside your body and check for any abnormal changes. They can also take samples of tissue from your body using a scope with instruments on the end.
Blood tests: These can help to diagnose some cancers. For example, they can detect substances called tumour markers which may be caused by cancer.
Biopsies: A biopsy is a sample of tissue taken from your skin or inside your body. The sample is then examined under a microscope to see if there are any cancer cells. A biopsy is usually needed to make a definite diagnosis of cancer.

If you want to know how a particular cancer type is diagnosed, please pick the type you are interested in on our cancer types page.

If you’re diagnosed with cancer…

Being told you have cancer is a huge shock. You may feel overwhelmed by emotions like anger, sadness, confusion, anxiety or even guilt. We have more information on coping with your emotions

Getting support after a cancer diagnosis

Getting some support can help you at this difficult time. The following people may help you to cope with your emotions or give you more information about your cancer and ways to cope.

Our cancer nurses – visit a Daffodil Centre or call our Support Line on 1800 200 700 to talk in confidence. You can email our cancer nurses at supportline@irishcancer.ie
Your specialist nurse or a medical social worker at the hospital.
An Irish Cancer Society Survivor Support volunteer, who has had a cancer diagnosis and really knows what you are going through. Our cancer nurses can put you in touch with a volunteer.
Other people going through the same thing. Join our online community at www.cancer.ie/community.
Your local cancer support centre.

We have more information on getting emotional support and talking about your cancer.

Tests after diagnosis

If you have been diagnosed with cancer, you may need more tests to give your doctor more information about your cancer. For example, the size of the cancer and if it has spread to other tissues. This is called staging. Staging helps your doctor to decide on the best treatment for you. Scans like MRI and PET can help to stage a cancer.

Read about your cancer type to see what staging tests might be recommended for you.