Hyperthyroidism, also known as overactive thyroid, is a type of thyroid disease that occurs when the thyroid gland overproduces hormones.Located at the base of the neck, the thyroid makes hormones that affect your metabolism (how the body uses energy) and other processes. When these hormones are overproduced, many of the body's functions speed up. People with an overactive thyroid may experience rapid heart rate, sudden weight loss, hair loss, and numerous other symptoms.

Though it may be a challenge to pinpoint the cause of hyperthyroidism, once it’s determined, the disorder can be effectively treated.

What’s the Difference Between Hyperthyroidism and Hypothyroidism?

While hyperthyroidism indicates an overactive thyroid, hypothyroidism means your thyroid is underactive, or not producing enough thyroid hormone. The symptoms of hypothyroidism are often the opposite of hyperthyroidism — instead of a revved-up metabolism, you will instead experience symptoms related to a sluggish metabolism.
Both conditions can cause fatigue and hair loss, but people with hyperthyroidism may experience weight loss, missed periods, and anxiety, while those with hypothyroidism experience weight gain, depression, and heavy menstrual cycles.
Hypothyroidism is also far more common than hyperthyroidism, affecting about 1 in 20 people in the United States. As with hyperthyroidism, it’s more common in women.
Diagnosing and treating hypothyroidism is a bit more straightforward: If your doctor sees you don’t have enough thyroid hormones in your lab work, she will put you on thyroid hormone replacements, such as Synthroid (levothyronxine).

On the other hand, hyperthyroidism can be a bit more challenging to control and treat — you may end up developing hypothyroidism after treatment. Once your doctor has diagnosed hyperthyroidism though, you can be on your way to recovery.

Learn More About the Difference Between Hyperthyroidism and Hypothyroidism

Causes and Risk Factors of Hyperthyroidism

The following are the most common causes of hyperthyroidism.

Graves’ disease This autoimmune disorder is the most common cause of hyperthyroidism. With Graves’ disease, your body stimulates the thyroid tissue to become overactive. This condition can also lead to Graves’ ophthalmopathy, which affects tissues and muscles behind the eyes. Graves’ disease can be hereditary, and it’s more common in women.
Thyroiditis Also known as an inflamed thyroid gland, this condition can be painless or painful. Thyroid dysfunction may be temporary or permanent. Painful thyroiditis is often preceded by a viral illness. Women are at a higher risk of painless thyroiditis in the year following pregnancy, a condition called postpartum thyroiditis.

Immunotherapy Drugs Tied to Thyroid Problems

Thyroid nodules Nodules are typically noncancerous growths within the thyroid. These lumps on the thyroid can become “toxic,” meaning they produce too much thyroid hormone. In time, this can lead to hyperthyroidism.Thyroid nodules may be solitary or come in multiples.

A high-iodine diet There’s no shortage of iodine in the American diet. While this mineral is necessary in small amounts, excess iodine (which can happen when a medication such as amiodarone is taken) may lead to hyperthyroidism. This cause of hyperthyroidism is rare.

Top Risk Factors for Developing Hyperthyroidism

Hyperthyroidism stems from a number of genetic, environmental, or individual health factors. The most common risk factors for developing hyperthyroidism include:
  • Being female, as thyroid conditions are more prominent in women
  • Having an autoimmune disease (including type 1 diabetes)
  • Having a family history of Graves’ disease or other autoimmune diseases
  • Hypothyroidism that’s overtreated (too much thyroxine medication)

Learn More About the Causes and Risk Factors for Hyperthyroidism

How Is Hyperthyroidism Diagnosed?

To diagnose hyperthyroidism, your doctor may perform one or more of the following tests and procedures.

Physical exam First, your doctor may feel the base of your neck to see if your thyroid gland is swollen or enlarged. She may also check to see if you have tremors, bulging of the eyes, overactive reflexes, and a rapid heart rate.
Blood tests Thyroid disorders are commonly diagnosed with a blood test. Your doctor will measure blood levels of the thyroid hormone thyroxine (T4), as well as a pituitary gland hormone called thyroid-stimulating hormone (TSH). With hyperthyroidism, you will likely have high T4 but low TSH levels. Your doctor may also order a blood test to measure another thyroid hormone, triiodothyronine (T3), as well as thyroid antibodies, which the body makes when the immune system mistakenly attacks the thyroid (as is the case with Graves’ disease).
Radioactive iodine uptake and thyroid scan This is used to determine how much iodine your thyroid takes up and at what rate hormones are produced. The radioactive iodine uptake test is done by taking a small amount of radioactive iodine and using a noninvasive device called a gamma probe to check the thyroid up to 24 hours later.The amount and distribution of iodine that your thyroid takes up can help to indicate the cause of hyperthyroidism.
Ultrasounds To get an even better view of your thyroid gland, your doctor may order an ultrasound.

Duration of Hyperthyroidism

The duration of hyperthyroidism depends on the underlying cause. For many people, hyperthyroidism is a chronic, or lifelong, condition. Once it's treated, you must recheck your thyroid levels to ensure you’re getting the correct amount of medication. For example, if you take anti-thyroid drugs, your doctor may decrease the dosage over one to two years, but you may need the medications for several years.
In the case of thyroiditis, hyperthyroidism may be more short term, lasting about three months. After this time, you may develop hypothyroidism that can last at least a year, sometimes becoming permanent.

Diet and Lifestyle Tips for Managing Hyperthyroidism

While you can’t fix hyperthyroidism via natural remedies, healthy diet and lifestyle measures can help ease hyperthyroid symptoms.

Your diet affects all aspects of your health, and what you do (and don’t) eat can also affect your thyroid gland. As a rule of thumb, you should eat whole foods as much as possible. Your doctor may also recommend a low-iodine diet, especially if you are scheduled to start radioactive iodine treatments. Too much iodine can interfere with hyperthyroidism recovery by increasing the amount of iodine your thyroid gland or any “hot” nodules (nodules that are producing excessive thyroid hormone) take up, and thereby increase thyroid hormones. Iodine is prevalent in foods from the ocean, as well as dairy, processed meats, and packaged foods.
Since hyperthyroidism can cause unintentional weight loss in some people, your doctor may recommend adding more protein to your diet or taking nutritional supplements. This ought to be done with caution though, as you are likely to gain weight back naturally once your condition is properly treated.
Regular low- to moderate-intensity exercise can help ease symptoms of hyperthyroidism. It can reduce feelings of anxiety and nervousness, while also helping you sleep better at night. Strengthening exercises can help reduce the chance of bone loss, which is sometimes seen with Graves’ disease.The key is to start off slow. Exercise that’s too intense can cause trouble, especially if you have heart palpitations from hyperthyroidism.

Hyperthyroidism and Mental Health

Finally, relaxation and stress management can go a long way in treating any disease, especially hyperthyroidism.The more you’re able to manage stress, the less severe some of your symptoms might be, especially anxiety and fatigue.

Learn More About Diet and Lifestyle Tips for Hyperthyroidism

Complications of Hyperthyroidism

Thyroid diseases are treatable. The key is to diagnose them early to prevent long-term complications. Hyperthyroidism isn’t considered life-threatening. But when left untreated, an overactive thyroid can lead to serious complications.

Complications of untreated hyperthyroidism include:

Heart-health issues Among some of the most serious hyperthyroid-related complications have to do with your heart health. Too much thyroid hormone makes your heart work harder, and this wear-and-tear can lead to a number of cardiac issues. Among these are:
  • High blood pressure (hypertension)
  • Abnormal heartbeat (arrhythmia)
  • Weakened heart muscle and increased cavities (cardiac dilation)
  • Cardiac arrest
  • Heart failure
  • Stroke
Osteoporosis Hyperthyroidism can cause more rapid bone breakdown. In the long term, this can lead to depleted bone mass and possible fractures.
Eye-health issues Certain forms of hyperthyroidism, such as Graves’ disease, can lead to long-term eye health problems. Graves’ ophthalmopathy is perhaps the most notable. This condition can consist of red, swollen eyes that also appear to be larger than normal. Blurred vision and sensitivity to light is also possible. When left untreated, Graves’ ophthalmopathy may lead to permanent vision loss.

Asian and Pacific Islanders, Black People, and Hyperthyroidism

Past research has indicated that Graves’ disease tends to be more prevalent in certain communities — particularly in non-Hispanic Black people, as well as Asians and Pacific Islanders.It’s not clear whether this prevalence is related to genetics or environmental exposures.

Related Causes and Conditions of Hyperthyroidism

Although there’s no single cause for an overactive thyroid, hyperthyroidism may occur in people with the following conditions:
  • Overtreated hypothyroidism
  • A recent pregnancy within the last six months
  • Type 1 diabetes
  • Primary adrenal deficiency
  • Pernicious anemia from vitamin B12 deficiency
  • Iodine overdoses from eating too many iodine-rich foods or taking iodine supplements

Hyperthyroidism Resources We Love

Favorite Organizations for Essential Hyperthyroidism Info

Hormone Health Network (Endocrine Society)

If you’re newly diagnosed with hyperthyroidism, we recommend reading this overview from the Endocrine Society right away. You may even consider it a one-stop shop for key management info on symptoms, treatment, and causes. As a bonus, the Endocrine Society has a list of recommended questions to ask your doctor so you can go into your next appointment prepared to advocate for yourself.

National Institute of Diabetes and Digestive and Kidney Diseases

Wondering about treatment side effects or if your hyperthyroidism is hereditary? This overview on hyperthyroidism from the National Institute of Diabetes and Digestive and Kidney Diseases is a good starting point. This resource also covers important information on hyperthyroidism and pregnancy.

American Thyroid Association

The American Thyroid Association is one of the longest-serving thyroid organizations around, so it’s no wonder we’ve picked this resource for their expertise. Bookmark this hyperthyroidism review article for information on diagnosis, treatment, symptoms, and causes of the condition. You’ll find yourself better equipped to talk to your doctor at your next appointment.

Favorite Integrative Sources for Hyperthyroidism

American Thyroid Association (ATA)

As with many other chronic health conditions, hyperthyroidism can’t be cured with alternative remedies alone. Still, some complementary treatments may help alleviate your symptoms. If you’re curious about complementary hyperthyroid treatments, read up on what the American Thyroid Association has to say, and talk to your endocrinologist for more information.

Favorite Hyperthyroidism Online Support Networks


While we’ve found numerous blogs related to thyroid health, Drugs.com is one of the few places that offers online networking specifically for people with hyperthyroidism. Here you can post questions and provide helpful insights to other hyperthyroid patients who need advice. While you’re there, you can read up on some of the latest hyperthyroidism-related news from Drugs.com.

Graves' Disease & Thyroid Foundation

This resource aims to educate people about Graves’ disease. Topics you can read up on include general treatments, anti-thyroid drug experiences, symptom relief, complications, and more.

Favorite Sites for Hyperthyroidism Diet Advice

Harvard Medical School

For quick and easy-to-follow diet pointers, check out this handy guide from Harvard Medical School. Here you can learn about the roles that fiber, iodine, fats, and carbs all play in your thyroid health. We also consider this a good starting point for discussing your dietary needs with your endocrinologist.


If you’ve got the basics down, now it’s time to learn more about what specific foods may help your hyperthyroidism. Endocrine Web’s slideshow covers the five must-have foods to add to your grocery cart for potential hyperthyroid relief.

Favorite Hyperthyroidism Apps


Not only is hyperthyroidism associated with anxiety, but managing it can be increasingly stressful over time. For on-the-go de-stressing approaches, the free app Breathe2Relax, which you can download on the App Store and on Google Play, has you covered. Its program teaches a stress-busting tool called diaphragmatic breathing and offers expert tips on how to elongate your breath. Stress management is key to managing any chronic illness, including thyroid disease.

Favorite Clinical Trial Outreach


Are you looking for a way to participate in clinical research groups for your condition? With your endocrinologist’s consent, you may be able to participate in selected studies in your area while gaining potential treatment. Bookmark the above link from the Endocrine Web to stay updated on all active clinical trials pertaining to hyperthyroidism.

Learn More About Resources for Hyperthyroidism

Editorial Sources and Fact-Checking

  • Hyperthyroidism (Overactive Thyroid). Mayo Clinic. November 14, 2020.
  • Hyperthyroidism (Overactive). American Thyroid Association.
  • Hyperthyroidism. National Institute of Diabetes and Digestive and Kidney Diseases. August 2016.
  • Hyperthyroidism. Children’s Hospital of Philadelphia.
  • Thyroid Disease. Office on Women’s Health. April 1, 2019.
  • Thinking About Your Thyroid: Get to Know This Small but Mighty Gland. National Institutes of Health: News in Health. September 2015.
  • Thyroid Function Tests. American Thyroid Association.
  • Thyroid Tests. National Institute of Diabetes and Digestive and Kidney Diseases. May 2017.
  • Radioactive Iodine Uptake. MedlinePlus. July 10, 2019.
  • Types of Thyroid Nodules and Cancers. NYU Langone Health.
  • Hyperthyroidism Complications. EndocrineWeb. May 7, 2019.
  • Low Iodine Diet. American Thyroid Association.
  • Uncontrolled Thyroid: Exercise, Diet Risks. Cleveland Clinic. October 31, 2013.
  • How to Manage Stress if You Have Autoimmune Thyroid Disease. EndocrineWeb. June 8, 2020.
  • Hyperthyroidism (Thyrotoxicosis). Merck Manual: Consumer Version. October 2020.
  • Dong BJ. How Medications Affect Thyroid Function. Western Journal of Medicine. February 2000.
  • Thyroid Function Tests. Clinical Thyroidology for the Public. December 2018.
  • Q and A: Can Thyroid Disease Be Cured? American Thyroid Association.
  • Lillevang-Johansen M, Abrahamsen B, Jørgensen HL, et al. Duration of Hyperthyroidism and Lack of Sufficient Treatment Are Associated With Increased Cardiovascular Risk. Thyroid. March 2019.
  • Hyperthyroidism: Prevention. Cleveland Clinic. April 19, 2020.
  • Thyroid Disease Risk Varies Among Blacks, Asians, Whites. ScienceDaily. April 15, 2014.
  • Della Volpe, K. Prevalance of Graves' Disease Varies Widely by Race/Ethnicity. EncocrineWeb. July 9, 2015.


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