Usually you begin by seeing your GP (family doctor) who will examine you and arrange for you to have any further tests or x-rays that may be necessary. Your GP will need to refer you to hospital for these tests and for specialist advice and treatment.
At the hospital the doctor will take your full medical history before doing a physical examination. A blood test and chest x-ray may be taken to check your general health.
A definite diagnosis is made by removing an enlarged lymph node or part of it and examining the cells under a microscope. This is known as a biopsy. It is a small operation, usually done under general anaesthetic.