What Is Thyroid Cancer?

Medically Reviewed by Jennifer Robinson, MD on September 13, 2022
3 min read

Your thyroid is shaped like a small butterfly, and is usually found inside the lower front of your neck. It’s a gland that controls your metabolism. It also releases hormones that direct many functions in your body, including how you use energy, how you produce heat, and how you consume oxygen.

Thyroid cancer develops when cells change or mutate. The abnormal cells begin multiplying in your thyroid and, once there are enough of them, they form a tumor.

If it’s caught early, thyroid cancer is one of the most treatable forms of cancer.


Researchers have identified four main types:

Papillary thyroid cancer. If you have thyroid cancer, you probably have this type. It’s found in up to 80% of all thyroid cancer cases. It tends to grow slowly, but often spreads to the lymph nodes in your neck. Even so, you have a good chance for a full recovery.

Follicular thyroid cancer makes up between 10% and 15% of all thyroid cancers in the United States. It can spread into your lymph nodes and is also more likely to spread into your blood vessels.

Medullary cancer is found in about 4% of all thyroid cancer cases. It’s more likely to be found at an early stage because it produces a hormone called calcitonin, which doctors keep an eye out for in blood test results.

Anaplastic thyroid cancer can be the most severe type, because it’s aggressive in spreading to other parts of the body. It’s rare, and it is the hardest to treat. 

If you have thyroid cancer, you probably didn’t notice any signs of it in the early stages. That’s because there are very few symptoms in the beginning.

But as it grows, you could notice any of the following problems:

  • Neck, throat pain
  • Lump in your neck
  • Difficulty swallowing
  • Vocal changes, hoarseness
  • Cough

There is no clear reason why most people get thyroid cancer. There are certain things, though, that can raise your odds of getting it.

Inherited genetic syndromes. Some conditions, including cancer, come from the DNA you get from your parents. In 2 out of 10 cases of medullary thyroid cancer, for example, the cancer is a result of an abnormal gene you’ve inherited.

Iodine deficiency. If you don’t get much of this chemical element in your diet, you could be at more risk for certain types of thyroid cancer. This is rare in the United States because iodine is added to salt and other foods.

Radiation exposure. If your head or neck was exposed to radiation treatment as a child.

Thyroid cancer is more common in women than men. Women tend to get thyroid cancer in their 40s and 50s, while men who get it are usually in their 60s or 70s.

Follicular thyroid cancer happens more often in whites than blacks and in more women than men.

You can still get thyroid cancer if you’re younger. Papillary thyroid cancer, for example, happens most often in people between ages 30 and 50.

Thyroid cancer is usually very treatable, even if you have a more advanced stage of it. That’s because there are effective treatments that give you a great chance for a full recovery. And surgery, when it’s needed, can sometimes cure it.