A number of tests may be performed to investigate symptoms of thyroid cancer and confirm a diagnosis. Some of the more common tests include:  

• physical examination and patient history 
• blood tests to check thyroid and other hormone levels and help identify non-cancerous thyroid conditions^[24] 
• imaging tests of the thyroid, which may include ultrasound scan, computerised tomography (CT) scan, magnetic resonance imaging (MRI) or positron emission tomography (PET) scan^[25] 
• nuclear medicine imaging such as a radioiodine scan, which involves taking a weak radioactive substance to show any abnormalities clearly 
• internal examination of the voicebox using a laryngoscope – a thin tube with a light on the end of it 
• removal of a small piece of tissue from the thyroid gland or a thyroid nodule (biopsy) for examination under a microscope 

There are a number of conditions that may cause these symptoms, not just thyroid cancer. If any of these symptoms are experienced, it is important that they are discussed with a doctor.