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The thyroid is a gland located in your neck, just above the collarbone. The thyroid gland makes hormones that control the rate at which your body performs certain tasks, including how your body uses energy. Hyperthyroidism is when your thyroid is too active, and makes more thyroid hormones than your body needs, which may cause your heart to beat fast, make you lose weight quickly, and other health problems.

What is Hyperthyroidism?

The thyroid [THAHY-roid] is a gland located in your neck, just above the collarbone and just below the Adam’s apple. The thyroid gland makes hormones that affect:

  • Heart rate
  • Breathing
  • Body temperature
  • Digestion
  • Metabolism [muh-TAB-ah-liz-um] – how the body makes and uses energy from food

Hyperthyroidism [hahy-per-THAHY-roi-diz-uhm] is when your thyroid is too active and makes more thyroid hormones than your body needs. When this happens, your heart may beat faster than normal (or be irregular), and you may burn calories very quickly, which may cause you to lose weight very quickly. Too much thyroid hormone can also make you feel nervous or irritable, and it may make you sweat a lot.


Hyperthyroidism has symptoms that are similar to other conditions. If you notice any of the following symptoms, it is important to go see your doctor so you can rule out other conditions, and also begin treatment. Some of the symptoms of hyperthyroidism include:

  • Rapid heartbeat
  • Increased appetite
  • Rapid or sudden weight loss even if your food habits or diet don’t change
  • Tremors (usually in the hands and fingers)
  • Increased sensitivity to heat
  • Changes in bowel patterns (often leading to more frequent bowel movements)
  • Diarrhea
  • Sweating
  • Nervousness
  • Anxiety
  • Irritability
  • Skin thinning
  • Fine, brittle hair
  • Changes in the menstrual cycle
  • Enlarged thyroid gland
  • Fatigue
  • Muscle weakness
  • Insomnia, or a hard time sleeping and staying asleep

Older adults that develop hyperthyroidism tend to have very few, if any symptoms.

When to See a Doctor

See a doctor if you have any signs or symptoms of hyperthyroidism.


Hyperthyroidism has several causes. Common causes include:

  • Graves’ disease. The body’s immune system attacks the thyroid gland, and the thyroid gets bigger and releases extra hormones. Graves’ disease is the most common cause of hyperthyroidism.
  • Thyroid nodules: A growth or lump forms on the thyroid causing the gland to produce too much thyroid hormone. There are many types of nodules that can form, but only a few tend to cause hyperthyroidism, such as hyperfunctioning [hi-per-FUNK-shun-ing] thyroid nodules or Plummer's disease
  • Thyroiditis. Thyroiditis is an inflamed or swollen thyroid gland. As a result, the thyroid releases too much hormone. Thyroiditis can be caused by an infection, taking certain medicines, or even pregnancy.

Diagnosis and Tests

To help diagnose hyperthyroidism, your doctor will likely give you a physical exam. During the physical exam, your doctor will test your reflexes, look for any tremors in your fingers, look for changes in your eyes, examine your skin, and examine your thyroid gland.

During the exam, your doctor may also ask you questions to help understand more about your symptoms and the changes in the body:

  • When the symptoms started
  • If your symptoms are constant or every now and then
  • How severe your symptoms are
  • If there is anything that helps improve your symptoms
  • If there is anything that makes your symptoms worse
  • If you have a family history, or other family members that have thyroid disease

Your doctor may also request blood tests to help diagnose a thyroid problem. If your blood test indicates that you may have hyperthyroidism, your doctor may call for a second test to confirm the diagnosis. Second tests may include:

  • Thyroid scan, which is where a radioactive isotope is injected into your body, and a special camera will work with the isotope to create an image of your thyroid gland, which your doctor will use to determine its health.
  • Radio iodine uptake test, where you are given a small dose of radioactive iodine, which will collect in the thyroid gland. Your doctor will check you every few hours to see how quickly the chemical is processed and use this information to evaluate your thyroid. 


Many different treatments are helpful in cases of hyperthyroidism. Your doctor will help you develop a treatment plan that is tailored to you, and will help you keep your condition under control. Some of the treatments your doctor may recommend include:

  • Anti-thyroid medicine, which will help prevent your thyroid from producing too much hormone.
  • Beta blockers, which will not reduce the amount of hormones your thyroid creates, but it can reduce your heart rate and prevent an irregular heartbeat.
  • Radioactive iodine, which is absorbed by the thyroid and causes it to shrink down to a more normal size, especially if it has been enlarged.
  • Surgery, which is where your doctor removes most of your thyroid gland. It is very uncommon.

Some at-home treatments that you can discuss with your doctor include:

  • Diet supplements, especially if you have lost a lot of weight
  • Making sure you get enough calcium and vitamin D


There is no way to prevent hyperthyroidism. However, treatment can help manage the condition. You can reduce your chances of developing some thyroid problems by:

  • Avoiding starvation (or other extreme) diets
  • If you smoke, stopping, and if you don’t smoke, not starting
  • Avoiding getting x-rays unless needed
  • Having regular check-ups so you can notice any changes quickly

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