Judging from its small size, the thyroid gland may not look important. The opposite is true, however. The gland produces hormones that the body needs for proper organ function, proper growth and proper energy use. In some cases, the thyroid can produce too much hormone, which can make a teenager feel overly energized and restless or it cannot produce enough hormone, which can lead to sluggishness.

Hyperthyroidism

When a teenager has hyperthyroidism, her thyroid is too active and makes too much thyroxine, the thyroid hormone. A teenager with hyperthyroidism may seem irritable or nervous. She may lose a great deal of weight, even though she eats a normal amount of food, or even more than an normal amount. Her heart may pound or beat very quickly or she may develop an abnormal heart beat. Her period may be irregular. Grave’s disease, an autoimmune disorder, causes many cases of hyperthyroidism in teenagers, according to KidsHealth. When a teenager has Grave’s disease, antibodies attack the thyroid and cause it to produce extra hormone. A teenager can take medication to keep her condition under control or can opt for radioactive iodine treatment, which destroys the gland. She can also have a portions of the gland surgically removed. After radioactive iodine or surgery, she will most likely need to take medication to replace the hormone.

Hypothyroidism

A teenager with hypothyroidism, or an underactive thyroid, may not have any symptoms at first. Left untreated, he may grow lethargic and feel as though he doesn’t have enough energy. He may gain weight, even if he eats a normal amount of food. Other symptoms include dry skin, a sensitivity to cold and depression. Puberty may be delayed as well, according to MayoClinic.com. An autoimmune disorder, Hashimoto’s thyroiditis, is the most common cause of hypothyroidism in teenagers, according to KidsHealth. When a teenager has Hashimoto’s thyroiditis, his body will attack the thyroid, causing it not to produce enough hormone. Usually, a teenager with an underactive thyroid will need to take a synthetic thyroid hormone medication.

Nodules

A nodule, or growth, on the thyroid usually will not cause any harm to a teenager. In some cases, a thyroid nodule could be cancerous, but that is rare in teenagers. Most teenagers will not know that they have a growth unless a doctor finds it during a routine examination. Sometimes, the nodule may grow large enough to be visible on the neck or may cause some throat pain. Nodules can either be due to swelling caused by autoimmune diseases, cysts or excess growth of the thyroid gland. Typical treatment for a non-cancerous nodule involves observation. A nodule of concern can be surgically removed.