Is Hyperthyroidism A Life-Threatening Condition?

Hyperthyroidism is a condition in which the thyroid gland produces too many hormones. Overactive thyroid affects about 1 out of 100¹ Americans ages 12 years and older. It has a variety of causes, but the most common is an autoimmune disease called Graves’ disease.

Have you considered clinical trials for Hyperthyroidism?

We make it easy for you to participate in a clinical trial for Hyperthyroidism, and get access to the latest treatments not yet widely available - and be a part of finding a cure.

What is hyperthyroidism?

Your thyroid gland, which is located at the front of your neck, produces hormones that control how your body uses energy as well as other functions. An overactive thyroid produces too many thyroid hormones, causing some of your body's functions to speed up. This hyperthyroid condition can affect you in a variety of ways.

What are the symptoms of hyperthyroidism?

Everyone's body reacts a little differently to fluctuations in thyroid hormones. This means that hyperthyroidism (overproduction of thyroid hormones) can present a variety of symptoms, which include:

Sometimes older adults experience different symptoms including withdrawal, depression, and loss of appetite.

Many of these symptoms can be caused by other health problems aside from or in addition to hyperthyroidism. Therefore, it's important to see your doctor if you have any of these symptoms.

What causes hyperthyroidism?

The most common cause of hyperthyroidism is Graves’ disease. This is an incurable autoimmune disorder that can also affect your eyes and skin. The risk factors for developing Graves' disease are:

  • Smoking or using other nicotine products

  • Having a family history of Graves' disease or other thyroid issues

  • Having other autoimmune diseases, especially vitiligo, autoimmune gastritis, type 1 diabetes, and rheumatoid arthritis

If you have these risk factors you should see your doctor immediately, especially if you develop symptoms of hyperthyroidism.

There are several other causes of hyperthyroidism, which include:

  1. Excessive consumption of iodine. This is most often found in people who take seaweed-based supplements, which can be very high in iodine. Some people are very sensitive to iodine. Thankfully, if this is the cause, then the symptoms typically go away and your thyroid returns to normal once you stop consuming excessive iodine.

  2. Overactive thyroid nodules. It's common to have benign (noncancerous) nodules in your thyroid gland, but sometimes one or more of them become overactive. This is most common in older adults.

  3. Thyroiditis. This results from inflammation in your thyroid gland, caused by an infection, autoimmune issues, or pregnancy.

  4. Overdosing on thyroid medication. Healthy levels of thyroid hormones can fluctuate with time and those taking thyroid medication for an underactive thyroid condition may experience symptoms of overactive thyroid (hyperthyroid). If you are on levothyroxine (a thyroid hormone replacement drug) for an underactive thyroid and experience hyperthyroid symptoms, talk to your doctor about your thyroid hormone levels and proper dosage.

  5. A noncancerous tumor of the pituitary gland in the brain. This is rare.

Is hyperthyroidism life-threatening?

Hyperthyroidism affects the balance of many systems in the body. Some complications due to untreated hyperthyroidism can, indeed, be life-threatening.

Complications of hyperthyroidism

Common complications of hyperthyroidism include:

  • Irregular menstrual cycle

  • Fertility problems

  • Osteoporosis

  • Muscle problems

  • Graves' ophthalmopathy, an eye disease that can lead to vision loss

  • Elevated risk of stroke and blood clots

  • Elevated risk of heart failure

The last two complications are caused by the rapid and irregular heartbeat common with hyperthyroidism and can be life-threatening. In addition, hyperthyroidism can negatively affect your quality of life in many ways.

Therefore, hyperthyroidism can be life-threatening and/or shorten your lifespan if you don't get the proper treatment to manage your condition.

Can hyperthyroidism be treated?

Some forms of hyperthyroidism are either self-limiting or can easily be treated.

Hyperthyroidism due to excessive consumption of iodine will resolve once the excessive consumption is halted. However, you may be advised to avoid certain foods high in iodine and possibly use non-iodized salt to keep it from coming back.

Postpartum hyperthyroidism (hyperthyroidism after having a baby) is typically followed by a period of hypothyroidism (low thyroid hormone levels), and self-resolves in most cases. Thyroid gland function typically returns to normal within 12 to 18 months after having a baby.

Thyroiditis (inflammation of the thyroid gland) is also sometimes self-resolving, especially if caused by an infection. With this, it is also fairly common for your thyroid to become underactive before returning to normal.

Graves' disease (an autoimmune condition resulting in overproduction of thyroid hormones, or hyperthyroidism), on the other hand, is a chronic condition for which there is currently no cure. There are three treatments typically used:

Antithyroid medications

Beta-blockers are often used for short-term thyroiditis as they reduce symptoms, and may be prescribed as a "gap" treatment for people with Graves' disease to ease symptoms while other medications start working.

The two medications prescribed for long-term use are methimazole and propylthiouracil. These do not result in a permanent cure, but in some cases, Graves' disease can go into remission. You might have to take these medications for years.

Radioiodine therapy

This is often the first line of therapy, although it is not recommended during pregnancy and when breastfeeding. Some people need more than one treatment.

You will receive oral radioactive iodine, which is taken up by the thyroid gland and results in damage to its cells, permanently reducing your production of thyroid hormones.

Most people who receive this therapy become hypothyroid and have to take a thyroid hormone replacement medicine called levothyroxine.


 Surgery is used when radioiodine therapy is not indicated or if a person has a large goiter (swelling of the thyroid gland). The surgical procedure removes part or the whole thyroid gland.

This treatment is less common, as it carries a higher risk, often leaves a visible scar, and can cause a condition called ‘thyroid storm’ in which your symptoms may get dramatically worse.

With surgery, many people are also likely to develop hypothyroidism and need lifelong thyroid hormone replacement therapy.

Once hyperthyroidism has been treated,  the risk of life-threatening complications is reduced or even eliminated. However, none of these treatments are a cure for overactive thyroid. Most people who have radioiodine therapy or surgery will need thyroid hormone replacement for life.

The lowdown

Hyperthyroidism can indeed be a life-threatening condition if left untreated. It can lead to heart failure and stroke, and other problems in your cardiovascular system. However, hyperthyroidism can be treated and managed, and in some cases may resolve over time if the cause is removed.

If you have symptoms of hyperthyroidism, especially if you carry risk factors, consult your doctor as soon as possible. A simple blood test can identify an overactive thyroid and allow you to seek treatment.

  1. Hyperthyroidism (Overactive thyroid) | National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

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