The thyroid is a small gland located at the base of your throat (near your Adam's apple) that regulates body functions such as heart rate, metabolism and the rate at which your body burns calories.
A thyroid nodule is a lump in the thyroid gland in your neck. More than 90% of all thyroid nodules are benign (non-cancerous). Some are actually cysts filled with fluid.
Almost 10% of adults will develop thyroid nodules in their lifetime. They are more common in women than in men. They also tend to run in families.
Most thyroid nodules do not cause symptoms. Some people might have trouble swallowing or have a feeling of fullness, pain or pressure in the throat or neck. Some people might notice a lump in their neck when they look in the mirror, but this is uncommon. Some people experience rapid unintended weight loss, feelings of nervousness or irregular heartbeat. Often, a doctor finds the lump during a routine checkup or during other tests.
Your doctor can do several different tests. One test is called fine-needle aspiration. Your doctor will take a tissue sample from your thyroid gland and examine it under a microscope to see if it is cancerous. The tissue sample is taken with a very small needle.
Another test your doctor may do is an ultrasound. This test uses sound waves to make a picture of the thyroid’s shape and the size of the nodules. It can help your doctor determine whether the nodule is a solid tumor or a cyst filled with fluid.
A third test is a thyroid scan. Your doctor will inject harmless radioactive iodine into a vein in your arm. The iodine is absorbed by your thyroid gland and makes it “glow” as your doctor takes a special picture. Your doctor can learn about the nodule depending on how much or how little of the iodine shows in the picture.
Some patients who have small benign nodules may choose watchful waiting. This is not a form of active treatment but rather an observation period. The nodule may go away on its own or stay the same size. Patients treated this way should be checked by their doctor every 6 months to monitor the growth of the nodule. As long as the nodule does not grow, there's usually no need to worry. Other forms of treatment include taking hormones or radioactive iodine to shrink the nodules or injecting the nodules with ethyl alcohol (ethanol) to shrink the nodules. If a nodule is cancerous or grows despite hormone pill treatment, surgery to remove the nodule may be needed.
Thyroid Nodules by MJ Welker, MD; D Orlov, MS, CNP (American Family Physician February 01, 2003, http://www.aafp.org/afp/20030201/559.html)
Written by familydoctor.org editorial staff
Reviewed/Updated: 07/10
Created: 04/03