For many people, the first stage of diagnosing thyroid cancer is a consultation with a GP.

Your GP will examine your neck and ask about any associated symptoms you may be experiencing, such as unexplained hoarseness.

Thyroid function test

A blood test known as a thyroid function test is used to check whether the swelling in your neck is caused by other problems with your thyroid gland.

It will rule out conditions such as an overactive thyroid gland (hyperthyroidism) or an underactive thyroid gland (hypothyroidism), which are the most common thyroid problems.  

A thyroid function test measures the amount of certain types of hormones in your blood.

Further tests will be needed if the thyroid function test reveals your thyroid gland is working normally.

Fine-needle aspiration cytology

Fine-needle aspiration cytology (FNAC) is the next stage in diagnosing thyroid cancer. It's an outpatient procedure, which means you won't have to spend the night in hospital.

A small needle is inserted into the lump in your neck to allow a tiny sample of cells to be removed. The sample is then studied under a microscope.

This test can usually reveal whether cancerous cells are present in your thyroid gland and, if they are, what type of thyroid cancer you have.

Further testing

Further testing may be recommended if the FNAC results are inconclusive or if further information is needed to make your treatment more effective. These tests may include:

• repeat FNAC combined with an ultrasound scan
• other types of scan, such as a computerised tomography (CT) scan or magnetic resonance imaging (MRI) scan

In most cases, surgery will be recommended to remove the part of the thyroid gland that contains the lump or swelling when it hasn't been possible to rule out thyroid cancer.