What are the risk factors for thyroid cancer?

  • Gender: Women are about three times more likely than men to develop thyroid cancer.
  • Age: In women, thyroid cancer is usually diagnosed in their 40s and 50s. Men are usually diagnosed in their 60s and 70s.
  • Family history (genetics): Thyroid cancer can sometimes run in families. Inheriting an abnormal gene can increase the risk of developing medullary thyroid cancer.
  • Exposure to radiation: Radiation treatments to the head and neck, especially treatments during childhood, can lead to thyroid cancer. Exposure to radiation can also come from fallout from a nuclear power plant accident. Tests that use radiation to make a medical diagnosis – such as dental X-rays or mammograms – do not cause thyroid cancer.
  • History of goiter: Goiter is an enlargement (growth) of the thyroid gland.
  • Lack of iodine: Iodine is necessary to produce thyroid hormone. Thyroid cancer is more common in parts of the world where there is a lack of iodine in the diet, such as central Asia and central Africa. In the United States, iodine is present in table salt and other foods, which lowers the risk of thyroid cancer.

Can thyroid cancer be prevented?

In many cases, it is not possible to prevent thyroid cancer. However, the following might help reduce or eliminate the risk of thyroid cancer:

  • Having prophylactic (preventive) surgery: Changes in certain genes can cause an increased risk of thyroid cancer. A person might choose to have his or her thyroid removed to prevent cancer from developing there.
  • Eating a healthy diet. A diet high in fruits and vegetables and low in animal fat can reduce the risk of many types of cancer. The American Cancer Society recommends eating at least five servings of fruits and vegetables every day. Unsaturated fats (omega-3 fatty acids), especially those found in salmon and other fish, might help protect against cancer. Maintaining a healthy weight can also help protect against many diseases, including cancer of the thyroid.

Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy