It's a good idea to see your GP if you have possible symptoms of thyroid cancer.
Your GP will examine your neck and ask about any other symptoms you may be experiencing, such as unexplained hoarseness.
If they think you might have a thyroid problem, they may arrange some tests or refer you to a hospital specialist.
The tests you may have are described below.
A blood test known as a thyroid function test is used to check the levels of thyroid hormones in your blood.
Further tests, such as an ultrasound scan, will be needed if the test shows that your thyroid gland is working normally.
An ultrasound scan is a type of scan that uses sound waves to create an image of the inside of your body. It's the type of scan used during pregnancy to check on the baby.
An ultrasound scan of your neck can be used to check for a lump in your thyroid that could be caused by cancer.
If a potentially cancerous lump is found, a biopsy will be carried out to confirm the diagnosis.
The only way to be sure whether a lump on the thyroid is cancer is to remove a small sample of cells from it and study them under a microscope. This is known as a biopsy.
This is usually done using a thin needle inserted into the lump. An ultrasound scan may be carried out at the same time to ensure the needle goes into the right place.
The procedure is usually carried out as an outpatient procedure, which means you won't have to spend the night in hospital.
If a biopsy finds that you have thyroid cancer, further tests may be needed to check whether the cancer had spread to another part of your body.
The main two tests used for this are:
After you're diagnosed with thyroid cancer, it will be possible to give your cancer a stage. This is a number that indicates how far the cancer has spread.
Doctors use a system called the TNM system to stage thyroid cancer. This consists of three numbers:
Knowing the stage of your cancer will help your doctors decide on the best treatment for you.
The Cancer Research UK website has more detailed information about the TNM staging system for thyroid cancer.