Below are listed some factors that may increase the risk of thyroid cancer but no one knows the exact causes of thyroid cancer.

1. Radiation exposure: People who are exposed to high levels of radiation are much more expected than others to have a thyroid cancer. One important source of radiation exposure is a treatment using x-rays. For example, a person who uses diagnostic x-ray frequently although by low dose radiation increases the risk to have thyroid cancer.
2. Gender: Thyroid cancer affects women more than male. In Peninsular Malaysia, as reported by Malaysian Cancer Statistics – Data and Figure, Peninsular Malaysia, 2006, female are three times more likely to have thyroid cancer than man.
3. Heredity: Certain types of thyroid cancer can be inherited.
4. Age: Thyroid cancer can occur in any age of groups, but it is more common after age 30, and the risk increases in older people.
5. Not enough iodine in the diet: The thyroid needs iodine to make thyroid hormone. We can reduce the risk if iodine be one of our food ingredients. Seafood is one of the examples that contain iodine.
6. Personal or family history of goiter: Goiter is a benign nodule (non-cancer tumor) of the thyroid. People with a goiter have a possibility to get thyroid cancer.

Having one or more risk factors does not mean that a person will get thyroid cancer. Most people who have risk factors never develop cancer. However, it is clear that thyroid cancer is not transmittable.

Updated:: 18/03/2019 []