What is Hyperthyroidism? What Are the Symptoms?

Just above your collarbone, at the bottom of your neck, is your thyroid. It’s a butterfly-shaped gland that controls things like how fast your heart beats and how quickly you burn off calories. It releases hormones to help regulate your body’s metabolism (all the things your body does to turn food into energy and keep you going).

Video Transcript

NIH.gov.<br>Nucleus Medical Media.

SUBJECT: Your thyroid gland is found just below your voice box or larynx. It wraps around your windpipe or your trachea. Your thyroid affects your metabolism. It makes hormones that affect how fast your whole body works and how it uses energy. Your body uses thyroid hormone to increase your energy and raise your body temperature when needed. For example, that helps replace the heat your body loses when exposed to cold weather.

If you have hyperthyroidism, it means your thyroid is overactive and produces too much of a hormone called thyroxine. It can significantly speed up your metabolism and cause unpleasant symptoms.

How Do I Know if I Have Hyperthyroidism?

Some common signs include:

  • Feeling nervous, anxious, or irritable
  • Experiencing mood swings
  • Feeling very tired or weak
  • Sensitivity to heat
  • An enlarged thyroid (goiter). This can make the base of your neck look swollen.
  • Losing weight suddenly with no known cause
  • Fast or irregular heartbeat or palpitations (pounding in your heart)
  • Increased frequency in your bowel movements
  • Shaking in your hands and fingers (tremor)
  • Sleep problems
  • Thinning skin
  • Changes in your hair that make it fine and brittle
  • Changes in your menstrual cycle

These are less likely to show up if you’re an older adult, but sometimes there will be subtle symptoms. These can include a faster heart rate or you could be more sensitive to hot temperatures. Or you could just feel more tired than usual from everyday activities.

Certain medicines can cover up the signs of hyperthyroidism. If you take beta blockers to treat high blood pressure or another condition, you might not know you have it. Be sure your doctor knows about all the medications you take.

When you first get hyperthyroidism, you may feel very energetic. This is because your metabolism is sped up. But over time, this increase in your metabolism can break your body down, and cause you to feel tired.

Usually, hyperthyroidism develops slowly over time, but if you’re young when you get it, the symptoms might come on suddenly.

Hyperthyroidism and Graves’ Disease

The most common cause of hyperthyroidism is an immune system disorder called Graves’ disease. It’s more likely to affect women under the age of 40.

In addition to the other symptoms of hyperthyroidism, about 30% of people with Graves’ disease develop a condition called Graves’ ophthalmopathy. It affects your eyes and vision, including the muscles and tissues around them. You may experience:

  • Bulging of your eyes (exophthalmos)
  • A gritty feeling or pain/pressure in your eyes
  • Redness or inflammation in or around your eyes
  • Puffiness or retraction of your eyelids
  • Sensitivity to light
  • Double vision or loss of vision

Sometimes people with Graves’ disease also develop a symptom called Graves’ dermopathy, but this is rarer. It involves redness and thickening of your skin, usually on the tops of your feet or your shins.

WebMD Medical Reference Reviewed by Carol DerSarkissian on May 09, 2019



Mayo Clinic: “Hyperthyroidism (overactive thyroid),” “Graves' disease.”

American Thyroid Association: “Hyperthyroidism (Overactive).”

MedlinePlus: “Hyperthyroidism.”

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