What Is the Thyroid? The thyroid is a small gland below the skin and muscles at the front of the neck, at the spot where a bow tie would rest. It's brownish red, with left and right halves (called lobes) that look like a butterfly's wings. It usually weighs less than an ounce. What Does the Thyroid Do? Though it's small, the thyroid does many important jobs, especially for teens. For instance, it: makes the hormones that help control metabolism and growth helps the body go through sexual development What Do Thyroid Hormones Do? Thyroid hormones are released from the gland and travel through the bloodstream to the body's cells. They help control the growth and the structure of bones, sexual development (puberty), and many other body functions. By helping cells convert oxygen and sugar and other body fuels into the energy they need to work properly, these hormones are important in helping a child's body mature as it should. Thyroid hormones also directly affect how most organs function. So a thyroid that isn't working as it should can cause problems in many other parts of the body. What Are the Types of Thyroid Disease? Thyroid disease happenss when the thyroid gland doesn't supply the proper amount of hormones needed by the body. This can cause: Hyperthyroidism If the thyroid is overactive, it releases too much thyroid hormone into the bloodstream. This is called hyperthyroidism. The body use up energy more quickly than it should, and chemical activity (like metabolism) in the cells speeds up. Graves' disease, an autoimmune disease, is the most common cause of hyperthyroidism. Read more about hyperthyroidism and Graves' disease. Hypothyroidism If the thyroid is underactive, it makes too little thyroid hormone, causing hypothyroidism. The body uses up energy more slowly, and chemical activity (metabolism) in the cells slows down. Hashimoto's thyroiditis is an autoimmune disease that causes most cases of hypothyroidism in kids and teens. Read more about hypothyroidism and Hashimoto's thyroiditis. Goiters and Thyroid Nodules Both hypothyroidism and hyperthyroidism can make the thyroid larger than normal. An enlarged thyroid gland is a lump that can be felt under the skin at the front of the neck. When it is large enough to see easily, it's called a goiter. A thyroid nodule is a lump or enlarged area in the thyroid gland. Read more about goiters and thyroid nodules. Thyroid Cancer Thyroid cancer is uncommon in children. When it does happen, the results of treatment are usually excellent. Read more about thyroid cancer. Back to Articles Related Articles Hyperthyroidism and Graves’ Disease Hyperthyroidism happens when the thyroid gland sends too much thyroid hormone into the blood. The most common cause of hyperthyroidism is Graves' disease. Read More Hypothyroidism and Hashimoto’s Thyroiditis An underactive thyroid makes too little thyroid hormone, causing hypothyroidism. Hashimoto's thyroiditis, which causes most cases of hypothyroidism in kids and teens, is a condition in which the immune system attacks the thyroid. Read More Goiters and Thyroid Nodules An enlarged thyroid gland is a lump that can be felt under the skin at the front of the neck. When it's big enough to see easily, it's called a goiter. A thyroid nodule is a lump or enlarged area in the thyroid gland. Read More Thyroid Cancer Thyroid cancer is uncommon in kids. Most who develop it do very well when the cancer is found and treated early. Read More Thyroid Tests Thyroid blood tests check thyroid function and can help doctors diagnose thyroid disorders such as hypothyroidism and hyperthyroidism. Read More Congenital Hypothyroidism Some babies are born with a thyroid gland that didn't develop correctly or doesn't work as it should. This is called congenital hypothyroidism. Read More Blood Test: Thyroid Peroxidase Antibodies The thyroid peroxidase antibodies test is primarily used to help diagnose and monitor autoimmune conditions involving the thyroid gland, including Hashimoto's thyroiditis and Graves disease. Read More Blood Test: T4 (Thyroxine) Doctors may order the T4 blood test if symptoms suggest any kind of thyroid disorder. Read More Blood Test: T3 Total (Triiodothyronine) The T3 total test is part of an evaluation of thyroid function. It's particularly useful in diagnosing hyperthyroidism, which can cause symptoms such as a fast heart rate, weight loss, trembling and sweating. Read More Blood Test: Thyroglobulin Antibodies (TgAb) The thyroglobulin antibodies test is used to help diagnose autoimmune conditions involving the thyroid gland, or when thyroid disorders are suspected. Read More Blood Test: Thyroid Stimulating Hormone (TSH) Doctors may order TSH blood tests to diagnose and monitor treatment of a thyroid disorder or evaluate pituitary gland functioning. Read More Blood Test: T3 Resin Uptake (T3RU) Doctors may order the T3 resin uptake when a child's symptoms or previous blood tests seem to suggest thyroid dysfunction. Read More Endocrine System The glands of the endocrine system and the hormones they release affect almost every cell, organ, and function of our bodies. Read More CAT Scan: Neck A neck CAT scan can detect signs of disease in the throat and surrounding areas. Doctors may order one to detect abscesses, birth defects, cysts, or tumors. Read More Endocrine System The endocrine system influences almost every cell, organ, and function of our bodies. It is instrumental in regulating mood, growth and development, metabolism, and sexual function, among other things. Read More Metabolism Your body gets the energy it needs from food through a process called metabolism. Get all the facts on metabolism in this article. Read More What Is the Thyroid? Do you know just how important the thyroid is? It helps you grow and affects your energy level. Read More Growth Problems In most cases, teens who are small are just physically maturing a bit more slowly than their friends. Occasionally, though, there's a medical reason why some kids and teens stop growing. Find out about growth problems and how doctors can help. Read More Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995-2021 KidsHealth®. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.