Health Library

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 weighs less than an ounce, but helps the body do many things, such as get energy from food, grow, and go through sexual development.

What Is Hyperthyroidism?

Thyroid hormone problems happen when the thyroid gland makes either too much or not enough thyroid hormone.

If the thyroid is overactive, it releases too much thyroid hormone into the bloodstream, causing hyperthyroidism. The body use up energy more quickly than it should, and chemical activity (like metabolism) in the cells speeds up.

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.

What Are the Signs & Symptoms of Hyperthyroidism?

High thyroid hormone levels (hyperthyroidism) can cause:

• nervousness
• irritability
• increased sweating
• bulging eyes
• trouble sleeping
• a fast heartbeat
• irregular menstrual periods in girls
• weight loss

Sometimes the thyroid gland grows and forms a bulge in the neck called a goiter.

Medicines and other techniques can effectively treat hyperthyroidism. It’s important to work with an

endocrinologist
(a doctor who specializes in hormone problems) or other doctor who knows how to treat thyroid conditions.

What Causes Hyperthyroidism?

The three main causes of hyperthyroidism are:

1. Graves’ disease. This is the most common cause of hyperthyroidism in children. It happens when the body produces antibodies that make the thyroid gland overactive. Antibodies usually help the body fight infection, but these antibodies stop the body from controlling the thyroid gland correctly (like a car without brakes). As a result, the thyroid hormone levels in the blood can get very high. Doctors don’t know why the body starts making these antibodies. Graves’ disease can affect health for the rest of a person’s life. So it’s important to get medical treatment to control it.
2. Thyroid gland inflammation (thyroiditis). This causes the thyroid gland to leak too much thyroid hormone into the blood. Thyroiditis can be caused by a lots of things — for example, a blow to the thyroid gland, infections, and

   autoimmune
   diseases (like Hashimoto’s thyroiditis). Hyperthyroidism from thyroiditis usually lasts for a few months and then gets better on its own. The thyroid usually recovers, but sometimes is damaged and can’t work normally again. This causes hypothyroidism (underactive thyroid).

3. Thyroid nodules (growths in the thyroid gland). These can sometimes make large amounts of thyroid hormones, causing symptoms of hyperthyroidism. Overactive thyroid nodules are usually large (an inch or more in size) and can be big enough to feel in the neck. Most overactive thyroid nodules are 

   benign
   and treated with surgery.

What Are the Signs & Symptoms of Graves’ Disease?

Kids and teens with Graves’ disease might notice that:

• they’re more tired than usual
• they have lots of trouble sleeping
• they lose weight
• their heart is beating very fast
• their hands shake (called tremor)
• they have a lot of trouble focusing

Girls with Graves’ disease sometimes notice that they have fewer (or less regular) menstrual cycles. Over time, many people notice that their thyroid glands are enlarged.

Some people with Graves’ disease have troubles with their eyes — itching, burning, redness, and sometimes trouble seeing normally. Sometimes they feel pressure behind the eyes, feel their eyes bulging, or see double. This is because the antibodies that make the thyroid overactive also cause

inflammation
and swelling behind the eyes. When this happens, it’s called Graves’ eye disease.

How Is Graves’ Disease Diagnosed?

Graves’ disease is diagnosed based on a visit with a doctor who will review the symptoms and examine the patient.

It’s important to do lab tests too, because many people can have some of the symptoms of hyperthyroidism for other reasons. Sometimes the blood tests aren’t enough to be sure of the diagnosis and other tests are needed, like a thyroid scan or ultrasound.

How Is Graves’ Disease Treated?

Doctors usually treat Graves’ disease with anti-thyroid medicines. These medicines slow the release of thyroid hormones from the gland. They usually bring hormone levels down to normal within a couple of months.

Many people with Graves’ disease need to take anti-thyroid medicines for a long time to control the condition — sometimes for the rest of their lives.

Some might need other treatment if anti-thyroid medicines don’t help or cause side effects, or if the disease is very hard to control. In these cases, two permanent treatment options can be used: radioactive iodine treatment and surgery.

Radioactive iodine (RAI) is the most commonly used permanent treatment for Graves’ disease. RAI damages the thyroid gland so that it can’t make too much thyroid hormone. This doesn’t harm other parts of the body. The RAI treatment is taken in capsules or mixed with a glass of water. The thyroid gland quickly absorbs the RAI from the bloodstream and, within a few months, the gland shrinks and symptoms slowly disappear.

Surgery to remove most of the thyroid gland is called a thyroidectomy. It’s done in a hospital under general anesthesia, so the person is asleep and feels nothing. A small incision (cut) in the lower central part of the neck usually leaves a thin scar. It’s common to have some pain for a few days after the surgery, but most people feel much better within a few days.

After treatment for hyperthyroidism, hormone production often slows down to hypothyroid (underactive) levels. So the person needs to take a thyroid hormone replacement tablet each day. This treatment is a lot easier to manage than taking pills to control the hyperthyroidism — fewer blood tests, doctor visits, and medicine changes are needed.

As the body adjusts to the hormone replacement tablets, a doctor may increase or reduce the dosage until the levels of thyroid hormone are normal. When the doctor finds the proper dosage, people usually feel well and free of symptoms. The doctor will continue to check hormone levels to make sure the dosage is right, especially for growing teens whose levels might change over just a few months.

What Else Should I Know?

We don’t know why people develop Graves’ disease. But with good medical help, kids and teens can be healthy and do all the things other kids and teens can do.

Graves’ eye disease can develop at any time in someone who has Graves’ disease. Smoke can make this eye disease much worse, so it’s very important to not smoke and to avoid secondhand smoke.

Women with Graves’ disease need to be very careful to keep their hormone levels in balance. Uncontrolled thyroid hormone levels in a pregnant woman can lead to problems during pregnancy and harm her baby.