What is thyroid cancer?

At the base of your neck is a butterfly-shaped gland that is your thyroid. The thyroid gland produces hormones that regulate your heart rate, metabolism, blood pressure, and body temperature. When abnormal cells begin to grow in the gland, they can cause thyroid cancer.

Thyroid cancer is an uncommon type of cancer. According to the National Cancer Institute, there are about 56,000 new cases of thyroid cancer in the United States every year. Experts are unsure what causes thyroid cancer. The disease is often treatable with surgery and chemotherapy.

There are different types of thyroid cancer:

  • Papillary thyroid cancer (PTC). This is the most common type of thyroid cancer. This type of thyroid cancer grows slowly and can spread to the lymph nodes in the neck.
  • Follicular thyroid cancer (FTC). This is the second most common type of thyroid cancer. This type of cancer can spread to the lungs.
  • Medullary thyroid cancer (MTC). This type of thyroid is less common.
  • Anaplastic carcinoma. This is a very rare and very aggressive form of thyroid cancer. It spreads quickly and is often fatal.
  • Thyroid lymphoma. This is a very rare form of lymphoma that starts in the thyroid gland.


Some people have no symptoms of thyroid cancer.

Thyroid cancer can cause any of the following signs or symptoms:

  • Swelling in the neck
  • A lump in the neck
  • Pain in the front of the neck
  • Changes to your voice that may not go away
  • Trouble swallowing
  • Trouble breathing*
  • A persistent cough

*If you are having trouble breathing, be sure to contact your healthcare provider immediately, or seek emergency care.

When to See a Doctor

If you have any of these signs or symptoms, talk to your doctor right away. Many of these symptoms can be caused by other underlying medical conditions.

More Information

Risk Factors

The cause of thyroid cancer is unknown. Certain risk factors for thyroid cancer include genetics, history of thyroid tumors, and exposure to high levels of radiation.