Diagnosing cancer

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Diagnosing cancer can involve lots of questions, a physical exam and multiple tests. Find out what to expect during the process of diagnosis and about some of the specialists you may see.

Key points

  • Cancer symptoms are sometimes similar to symptoms for more common illnesses, so it may take your doctors some time to diagnose you.
  • Diagnosis usually starts with answering questions and a physical exam. The doctor may refer you for tests including blood tests and scans.
  • If your doctor thinks that you may have cancer, they will refer you to an oncologist, who is a doctor who specializes in cancer.

What does diagnosis mean?


For more videos regarding teens and cancer, please visit the Teens Taking Charge Cancer playlist.

Doctors use a process called "making a diagnosis" to figure out what type of cancer you have and where the cancer cells are in your body. At the end of this process, they will tell you what type of cancer you have. This is called your diagnosis. For example, you might have a diagnosis of leukemia or a solid tumour, such as osteosarcoma (bone cancer).

Diagnosis can take time

Symptoms are signals from your body that something is wrong and that you should go to the doctor. Symptoms help the doctor make a diagnosis. The symptoms you have depend on the type of cancer you have and what part of your body the cancer is in. Sometimes cancer symptoms are the same as symptoms for other more common illnesses (like a cold), so it can take your doctors some time to figure out exactly what is wrong.

You may see lots of doctors and nurses while you are waiting for a diagnosis. It is very important that your health-care team takes the time to make the right diagnosis so they can give you the right treatment.

Waiting for a diagnosis can be scary. Understanding how cancer is diagnosed and the tests you may need can help you cope better.

How is cancer diagnosed?

Cancer is diagnosed by answering a lot of questions, a physical examination and many different tests. It usually takes a number of steps.

The first doctor you see may be your family doctor or an emergency room doctor. They may talk to you and your parents about how you are feeling. They will usually ask lots of questions. Then they will do a physical examination to check you from head to toe. They may arrange for you to have some other tests such as blood tests and scans (pictures of the inside of your body).


When your doctor considers that you may have cancer, they will likely send you to a specialist in a hospital. A specialist is a doctor who works with a specific type of illness. Some people also meet a surgeon who might perform a procedure called a biopsy. Cancer specialists are called oncologists (say: on-KOL-uh-jist). An oncologist may also specialize in pediatric cancers (cancers that occur in children and teenagers). The specialist will examine you again and do more tests. These tests will help the specialist make the right diagnosis.

Last updated: September 3rd 2019