You usually start by seeing your GP if you have symptoms. They will ask you about your symptoms and examine you.
They will then decide about whether to refer you for tests or to a specialist. You have further tests if you have cancer. These tests are to find out its size and whether it has spread. This is called staging.
You might have one or more of these tests to find out the cause of your symptoms, or to find out the size of your cancer and whether it has spread.