Am Fam Physician. 2013;88(3):online
See related article on thyroid nodules
What is the thyroid?
The thyroid is a small gland in the front of your neck, just above the breastbone (see drawing). It controls your body temperature and the rate at which your body uses calories.
What is a thyroid nodule?
A thyroid nodule (NOD-jool) is a small lump in the thyroid. It may be solid or filled with fluid. Some nodules make too much thyroid hormone and cause symptoms such as shakiness, rapid heart rate, anxiety, and weight loss.
Who gets them?
Doctors do not know what causes thyroid nodules. They are rare in children. They are more common in people with certain thyroid diseases, in pregnant women, and in people who have low levels of iodine in their diet.
How can I tell if I have a thyroid nodule?
Most thyroid nodules do not cause symptoms, so people usually don't know they have one. Sometimes small nodules that can't be felt are found when an ultrasound or CT scan is done on the neck for another reason. Nodules larger than 1 cm (about half an inch) can often—but not always—be felt by your doctor during an exam. Large nodules can sometimes feel like pressure in your neck, and can make you have trouble swallowing or feel like you are choking.
What happens if my doctor finds a thyroid nodule?
Your doctor will check your thyroid hormone level. If it is too high, the next step is to have a thyroid scan. You may also need an ultrasound to see how big the nodule is and if there are any others. If you have a large nodule, you may need a biopsy. This is done by passing a small, hollow needle into the nodule and removing a small piece to be examined under a microscope.
How are thyroid nodules treated?
If you have a nodule that is not causing symptoms and the biopsy does not show any signs of cancer, your doctor may want you to have follow-up ultrasounds to make sure the nodule isn't growing. You may need surgery if you have a large nodule that is causing symptoms.
Nodules that make too much thyroid hormone are usually treated with radioactive iodine. This is a pill that destroys the nodules without damaging any surrounding tissue.
Are thyroid nodules serious?
Most nodules are not serious, but cancer is found in about one out of 10. The risk of cancer is much higher if you have had radiation treatments to your head or neck (not including x-rays or CT scans). Doctors don't know what the risk of cancer is for smaller nodules that can't be felt, but it is probably much lower than it is for larger ones.
Where can I get more information?
Your doctor
American Association of Clinical Endocrinologists
American Thyroid Association
