Hyperthyroidism

Hyperthyroidism is a condition in which your thyroid creates and releases more hormones than you need. This is also called overactive thyroid. The main hormones your thyroid makes include triiodothyronine (T3) and thyroxine (T4).

Causes #

Graves’ disease #

• In this disorder, your immune system attacks your thyroid.

• This makes your thyroid create too much thyroid hormone.

• Graves’ disease is a hereditary condition (passed down through a family).

• If a member of your family has Graves’ disease, there’s a chance others in the family could have it, too.

• It’s more common in people assigned female at birth than people assigned male at birth.

• Graves’ disease is the most common cause of hyperthyroidism, making up about 85% of cases.

Thyroid nodules #

A thyroid nodule is a lump or growth of cells in your thyroid gland. They can produce more hormones than your body needs. Thyroid nodules are rarely cancerous.

Thyroiditis #

• Thyroiditis is inflammation of your thyroid gland, which may be painful or painless (silent).

• It may happen within a year of delivering a baby (postpartum thyroiditis).

• After you experience thyroiditis, your thyroid may be unable to recover, which would lead to hypothyroidism.

Consuming excess iodine #

• If you’re at risk for hyperthyroidism and consume too much iodine (through your diet or medications), it can cause your thyroid to produce more thyroid hormone.

• Iodine is a mineral that your thyroid uses to create thyroid hormone. Receiving intravenous iodinated contrast (iodine dye) may also cause hyperthyroidism.

• Amiodarone, a medication that contains a high amount of iodine, may also cause hyperthyroidism.

Symptoms #

• Rapid heartbeat (palpitations).

• Feeling shaky and/or nervous.

• Weight loss.

• Increased appetite.

• Diarrhea and more frequent bowel movements.

• Vision changes.

• Thin, warm and moist skin.

• Menstrual changes.

• Intolerance to heat and excessive sweating.

• Sleep issues.

• Swelling and enlargement of the neck from an enlarged thyroid gland (goiter).

• Hair loss and change in hair texture (brittle).

• Bulging of the eyes (seen with Graves’ disease).

• Muscle weakness.

Diagnosis #

Radioactive iodine uptake (RAIU) test #

• For this test, you’ll take a small, safe dose of radioactive iodine (also called a radiotracer) by mouth to see how much of it your thyroid absorbs.

• After a certain amount of time usually at six and 24 hours later your healthcare provider will scan your neck with a device called a gamma probe to see how much of the radioactive iodine your thyroid has absorbed

• If your thyroid has absorbed a lot of the radioactive iodine, it means that your thyroid gland is producing too much thyroxine (T4).

• If this is the case, you most likely have Graves’ disease or thyroid nodules.

Thyroid scan #

• This procedure is an extension of the RAIU, where in addition to measuring the absorbed amount of radioactivity by your thyroid, you’ll lie on a table with your head tilted back while a special camera (gamma camera) takes several images of your thyroid.

• The radioactive material makes all or certain parts of your thyroid appear bright on the screen.

• Your provider may use a thyroid scan to look for lumps or nodules on your thyroid, inflammation, swelling, goiter or thyroid cancer.

Thyroid ultrasound #

An ultrasound uses high-frequency sound waves to create images of your thyroid. It’s a non-invasive procedure that allows your provider to look at your thyroid on a screen. Your provider may use this test to look for nodules on your thyroid.

Treatment #

Antithyroid drugs methimazole (Tapazole) or propylthiouracil (PTU) #

These drugs block the ability of your thyroid to make hormones. They offer rapid control of your thyroid.

Radioactive iodine #

• Radioactive iodine is an oral medication that your overactive thyroid cells absorb.

• The radioactive iodine damages these cells and causes your thyroid to shrink and thyroid hormone levels to go down over a few weeks.

• This usually leads to permanent destruction of the thyroid, which will cure hyperthyroidism.

• The amount of radiation delivered by this medication is different from the amount used for the radioactive iodine uptake (RAIU) test and scan for diagnosis.

• Most people who receive this treatment have to take thyroid hormone drugs for the rest of their lives to maintain normal hormone levels.

Surgery #

• Your healthcare provider may remove your thyroid gland through surgery (thyroidectomy).

• This will correct your hyperthyroidism, but it will usually cause hypothyroidism (an underactive thyroid), which requires lifelong thyroid supplements to keep hormone levels normal.

Beta blockers #

• These drugs block the action of thyroid hormones on the body.

• They do not change the level of hormones in your blood, but they can help control symptoms like rapid heartbeat, nervousness and shakiness that are caused by hyperthyroidism.

• This treatment isn’t used alone and is usually paired with another option to treat hyperthyroidism over the long term.