Risk Factors for Thyroid Cancer

A risk factor is something that raises a person's chances of getting a health problem. A person can have thyroid cancer with or without the risks below. The more risks a person has, the greater the chances are.

Thyroid cancer is more common in people 40 years or older. Anaplastic thyroid cancer is more common in people aged 60 years or older. Women are more likely to get thyroid cancer than men. But, men are more apt to get medullary thyroid cancer.

Other things that raise the risk of thyroid cancer are:

• Radiation exposure—especially to the head and neck. This is especially true for children or adolescents. The exposure could be from cancer treatments or repeated CT scans. It can also be from radioactive fallout. Examples are nuclear accidents or exposures at the World Trade Center site.
• Family history—Thyroid cancers tends to run in families. Risk is higher if a parent or sibling had the cancer.
• Certain inherited gene changes—With medullary thyroid cancer
• Medical conditions or syndromes such as:
  • Low iodine levels (follicular thyroid cancer)
  • History of thyroid cancer
  • Obesity, acromegaly, or Sjogren syndrome
  • Organ transplant

Thyroid cancer is also more common in people of Hawaiian and Polynesian descent.

Revision Information

• Reviewer: EBSCO Medical Review Board Mohei Abouzied, MD, FACP
• Update Date: 04/20/2022