What Are Thyroid Nodules?

Your thyroid is a small, powerful gland located in your neck. It makes thyroid hormone, which affects your metabolism, heart rate, and many other systems in the body. Sometimes, cells can grow out of control and form a lump on your thyroid. Doctors call these “thyroid nodules.” They may be solid or filled with fluid.

What Causes Them?

It’s not always clear why a person gets thyroid nodules. Several medical conditions can cause them to form. They include:

  • Thyroiditis: This is chronic inflammation of the thyroid. One type of thyroiditis is called Hashimoto’s disease. It’s associated with low thyroid activity (hypothyroidism).
  • Iodine deficiency: A diet that lacks iodine can result in thyroid nodules. This is uncommon in the U.S., since iodine is added to many foods.
  • Thyroid adenoma: This is an unexplained overgrowth of thyroid tissue. Most adenomas are harmless, but some produce thyroid hormone. This leads to an overactive thyroid (hyperthyroidism).
  • Thyroid cyst: This is usually caused by a thyroid adenoma that’s breaking down (“degenerating”).
  • Thyroid cancer: Most thyroid nodules aren’t cancer, but some can be.

Who’s At Risk?

Thyroid nodules are actually quite common. By the age of 60, half of all people have them. They’re often very small. You might only learn you have a thyroid nodule when your doctor feels for one during an examination or if you have an ultrasound of your thyroid.

Still, several things can increase your chances of developing a thyroid nodule. They include:

  • Living in a part of the world where the diet doesn’t include iodine
  • Having a family history of thyroid nodules
  • Being male
  • Being younger than 30 or older than 60

Do I Have a Thyroid Nodule?

You may be able to identify one just by looking in the mirror. Face the mirror with your chin raised a little. Swallow and look for a bump on either side of your windpipe near your Adam’s apple. Put your fingers gently on your neck in that spot and feel for a bump. If you find one, ask your doctor about it.


About 90% of thyroid nodules are benign (non-cancerous).

If you notice one, have your doctor check it. He’ll do a physical exam and might order one of the following tests to find out if it’s cancer or not:

  • Blood test for thyroid hormones
  • Ultrasound
  • Fine-needle biopsy

With a biopsy, your doctor will insert a very fine needle into your thyroid nodule to collect a few cells. He’ll send them to a lab for further study.

Non-cancerous thyroid nodules can still be a problem if they grow too large and make it hard for you to breathe or swallow.

What’s the Treatment?

If a thyroid nodule is benign and small, the usual treatment is “watchful waiting.” You’ll have ultrasounds of your thyroid from time to time to see if the nodule is growing. Your doctor will also check your thyroid hormone levels occasionally. If there’s a change, you may need medication to regulate them.

Any cancerous thyroid nodules should be removed surgically. The same is true for very large ones and those that change and develop strange features over time.

Nodules that make too much thyroid hormone may be treated with radioiodine. It’s radioactive iodine that can be taken in a pill or liquid form. It helps reduce the size of the thyroid nodule without harming other tissue. Other treatments may include anti-thyroid medicines and surgery.

WebMD Medical Reference Reviewed by Jennifer Robinson, MD on February 02, 2019



U.S. Department of Health and Human Services’ Office on Women’s Health: “Thyroid Disease.”

American Thyroid Association: “Thyroid Nodules.”

Mayo Clinic: “Thyroid Nodules: Overview,” “Thyroid Nodules: Causes,” “Thyroid Nodules: Diagnosis.”

© 2019 WebMD, LLC. All rights reserved.