What are the treatment options for an overactive thyroid?

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An overactive thyroid can be treated with medication, surgery or radioactive iodine. The most suitable treatment option will mainly depend on the cause of the disease.

If the thyroid gland makes too many and releases them into the bloodstream, it can lead to things like weight loss, nervous restlessness and a rapid heartbeat. An overactive thyroid (hyperthyroidism) can have various underlying causes. The most common of these is called Graves’ disease. It also often develops if cells in the thyroid gland start making too many "autonomously" – in other words, without being instructed to by the pituitary gland, which is normally the case. These autonomous cells are either found in a nodule (lump) or spread throughout the whole gland.

Mild hyperthyroidism may get better on its own, without treatment. In most cases, though, the symptoms get worse without treatment.

When are the different treatments considered?

If the thyroid gland is producing too many , the first step of treatment is usually to slow down the production of using medication. The hormone levels need to return to normal before other treatments can be started. The most suitable further treatment will depend on the cause:

  • If the overactive thyroid is being caused by "autonomous" thyroid cells, the next step of treatment is often radioiodine therapy.
  • If the thyroid gland has become very large, surgery to remove it is usually recommended.
  • In Graves' disease, taking medication for about a year is often enough. But surgery or radioiodine therapy are often needed to make the thyroid function return to normal over the long term.

The choice of treatment doesn't only depend on what is causing the overactive thyroid. For instance, the medication isn't always well tolerated, and some people would rather not have surgery. It is then a good idea to discuss the available treatment options with the doctor.

What are the medication options?

The main medications used for the treatment of an overactive thyroid are known as anti-thyroid drugs. These reduce the production of thyroid . Thiamazole (also called methimazole) and carbimazole are the most commonly used anti-thyroid drugs. If these drugs aren't tolerated, propylthiouracil is sometimes used. It's always a good idea to discuss the pros and cons of these drugs with your doctor. The most common side effects of anti-thyroids include skin rashes, fever and joint problems. If a fever arises, it's important to see a doctor immediately because the fever could be a sign of a blood disorder (agranulocytosis) – although this is rare.

Sometimes a medication called perchlorate is used instead. Perchlorate prevents iodine from being absorbed by the thyroid gland. Iodine is a trace element that the thyroid gland needs in order to produce . An overactive thyroid that has access to a lot of iodine can also produce more . Perchlorate is used in, for example, people who have an overactive thyroid and need to have an x-ray examination using an iodine-containing contrast medium (a dye-like substance) due to a different medical problem.

If the overactive thyroid causes a rapid or irregular heartbeat, a beta blocker (usually propranolol) can be taken too. People who have Graves' disease are sometimes given steroids.


If one single "autonomous" nodule is responsible for the thyroid being overactive, removing the nodule or the affected half of the gland is enough. If the whole gland is enlarged, and autonomous thyroid tissue or nodules are spread throughout it, the entire gland is usually removed. This is also done if someone needs surgery for an overactive thyroid caused by Graves' disease.

As well as the general risks associated with surgery – such as bleeding, wound infections or wound healing problems – there's a risk that a certain nerve (called the recurrent laryngeal nerve) may become damaged during surgery. This can cause hoarseness and, in very rare cases, breathing problems. Surgery may also cause damage to glands that regulate the balance in the body, known as parathyroid glands. These approximately lentil-sized glands are located on the back of the thyroid gland. If thyroid surgery causes hoarseness or problems affecting the function of the parathyroid glands, they are usually only temporary.

Radioiodine therapy

When the thyroid gland produces thyroid , it absorbs iodine from the blood. Radioiodine therapy makes use of this: Radioactive iodine (radioiodine) is swallowed in the form of a capsule or dissolved in water. It is then absorbed by the thyroid gland, where it destroys overactive cells. This reduces the production of thyroid . The amount of radiation is very low, and most of it leaves the body on its own within a few days. To avoid exposing other people and the environment to radiation, people who have radioiodine therapy in Germany stay in hospital for a few days. During this time, they stay in a special isolation room and generally aren't allowed to have visitors. The effects of radioiodine therapy only become noticeable after a few weeks.

Radioiodine therapy is not suitable for pregnant women and breastfeeding mothers. In people who have Graves' disease, radioiodine therapy might increase the risk of eye problems.

Although severe complications such as heart problems can occur in people who have radioiodine therapy, they are very rare. This can happen if the destroyed cells release stored thyroid , temporarily increasing the level of these in the blood. Because of this, people who are at higher risk of heart problems are advised to take anti-thyroid medication too if they have radioiodine therapy. Radioiodine therapy is currently not believed to increase the risk of cancer. But research in this area hasn't reached any clear conclusions.

Treatment can lead to an underactive thyroid

People who have thyroid surgery or radioiodine therapy often have an underactive thyroid gland (hypothyroidism) afterwards. This is particularly likely if a lot of the thyroid gland was removed or many gland cells were destroyed. In people who have Graves' disease, the aim of surgery or radioiodine therapy is actually to completely remove or destroy all of the thyroid gland tissue.

The thyroid gland is then no longer able to produce thyroid , so you usually have to take thyroid hormone tablets for the rest of your life. Taken at the right dose, the tablets are well tolerated. If the dose is too high, they may cause problems similar to the symptoms of an overactive thyroid, such as a rapid heartbeat.

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IQWiG health information is written with the aim of helping people understand the advantages and disadvantages of the main treatment options and health care services.

Because IQWiG is a German institute, some of the information provided here is specific to the German health care system. The suitability of any of the described options in an individual case can be determined by talking to a doctor. informedhealth.org can provide support for talks with doctors and other medical professionals, but cannot replace them. We do not offer individual consultations.

Our information is based on the results of good-quality studies. It is written by a team of health care professionals, scientists and editors, and reviewed by external experts. You can find a detailed description of how our health information is produced and updated in our methods.

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Updated on June 15, 2021

Next planned update: 2024


Institute for Quality and Efficiency in Health Care (IQWiG, Germany)

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