What is hyperthyroidism?

Hyperthyroidism means your thyroid gland makes too much thyroid hormone. Thyroid hormone controls how your body uses energy, also called metabolism. When you have too much thyroid hormone, your metabolism speeds up. You may lose weight quickly or feel nervous and moody. Or you may have no symptoms at all.

Too much thyroid hormone can also affect your heart, muscles, bones, and cholesterol.

Hyperthyroidism can occur at any age but rarely affects children. It affects women more often than men.

Your thyroid is a gland in the front of your neck.

You may have no symptoms of hyperthyroidism. Or:

• You may feel nervous, moody, weak, or tired.
• Your hands may shake, your heart may beat fast, or you may have problems breathing.
• You may be hot and sweaty or have warm, red, itchy skin.
• You may have more bowel movements than usual.
• You may have fine, soft hair that is falling out.
• You may lose weight even though you eat the same or more than usual.

Some women have irregular menstrual cycles or stop having periods altogether. And some men may develop enlarged breasts.

The symptoms of hyperthyroidism are not the same for everyone. Your symptoms depend on how much hormone your thyroid gland is making, how long you have had the condition, and your age.

People with Graves' disease often have other symptoms, such as a goiter and bulging, reddened eyes.

To diagnose hyperthyroidism, your doctor will ask questions about your past health and your symptoms and will do a physical exam.

If your doctor thinks you may have hyperthyroidism, he or she may order:

• A thyroid-stimulating hormone (TSH) test. This blood test measures your levels of TSH. If your TSH level is low, your doctor will want to do more tests.
• Thyroid hormone tests. These blood tests measure your levels of two types of thyroid hormones, called T3 and T4. If your levels are high, you have hyperthyroidism.

When you are being treated for this condition, your doctor will test your TSH and thyroid hormones several times a year to see how well your treatment is working.

Your doctor may also do tests that can help find the cause of your condition. These can include an antithyroid antibody test, a thyroid scan, and a radioactive iodine uptake test.

The best treatment for you will depend on a number of things, including your age. The treatments doctors use most often are:

• Radioactive iodine. Most people are cured after taking one dose. It destroys part of your thyroid gland, but it does not harm any other parts of your body.
• Antithyroid medicine. This works best if your symptoms are mild. These pills don't damage your thyroid gland. But they don't always work, and you have to take them at the same time every day. If they stop working, you may need to try radioactive iodine.

Sometimes surgery is needed. For example, you may need surgery if your thyroid gland is so big that you have a hard time swallowing or breathing.

If your hyperthyroidism symptoms bother you, your doctor may give you pills called beta-blockers. These can help you feel better while you and your doctor decide what your treatment should be.

To help reduce the symptoms of hyperthyroidism, you can:

• Lower stress. This helps relieve symptoms of anxiety and nervousness.
• Avoid caffeine. Caffeine can make some symptoms worse. These include fast heartbeat, nervousness, and trouble concentrating.
• Quit smoking. If you have Graves' disease and you smoke, you are more likely to develop Graves' ophthalmopathy.

Be sure to see your doctor regularly. Your doctor checks to be sure that your hyperthyroidism treatment is working, that you are taking the right amount of medicine, and that you aren't having any side effects.

If you have Graves' ophthalmopathy, you may need to use eyedrops to help moisten your eyes. And you may need to wear sunglasses to protect your eyes.