Hyperthyroidism

What Is Hyperthyroidism? Symptoms, Causes, Diagnosis, Treatment, and More

Kristeen Cherney, PhD
By Medically Reviewed by 
Reviewed:
Medically Reviewed
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.

Common Questions & Answers

Can you die from hyperthyroidism?
While hyperthyroidism itself isn’t fatal, it can lead to life-threatening complications when left untreated. These primarily involve your heart and may include arrhythmia, high blood pressure (hypertension), cardiac arrest, and congestive heart failure.
Is an overactive thyroid serious?
An overactive thyroid is a serious health condition because it places stress on major body systems — especially your heart. Hyperthyroidism is treatable, but when left undiagnosed or undertreated, it may lead to heart issues as well as osteoporosis in the future.
What is the TSH level for hyperthyroidism?
Thyroid stimulating hormone (TSH) is the most sensitive hyperthyroidism test. The normal TSH range can vary between labs, but generally is between 0.4 and 4 milliunits per liter (mu/l). While hyperthyroidism means your thyroid is in overdrive, a low TSH level indicates the disorder. TSH readings under 0.4 mu/l and high T4 hormone readings may, too.
How do you feel when you have hyperthyroidism?
Hyperthyroidism makes you feel like you’re in overdrive and restless, while also feeling fatigued and anxious at the same time. You may sweat more due to heat sensitivity, and you might experience a pounding heart coupled with tremors. You may have trouble falling asleep, too.
Are other family members at risk for hyperthyroidism?
It depends on whether your hyperthyroidism is related to an autoimmune disease. People with Graves’ disease tend to see a higher incidence of autoimmune conditions in their families, but not necessarily hyperthyroidism specifically.

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 levothyronxine (Synthroid).

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

Signs and Symptoms of Hyperthyroidism

Symptoms of hyperthyroidism can resemble those of other health problems, making the condition difficult to diagnose. In people older than 60, it may sometimes be initially misdiagnosed as depression or dementia, because older people may not show classic symptoms of hyperthyroidism.

Older adults, as well as people who take beta-blockers, are less likely to be diagnosed than younger adults. Beta-blockers in particular may mask symptoms.

Hyperthyroidism causes many functions in your body to speed up. People who have this condition may at first think they’re just stressed or nervous. This can cause a delay in diagnosis.

People with hyperthyroidism may experience the following symptoms:

  • Sudden weight loss that’s not intentional
  • An increase in appetite
  • Nervousness
  • Increased stress and anxiety
  • Heart palpitations
  • Increased heart rate
  • Sweating and tremors
  • Sleep difficulties
  • Fatigue (usually from insomnia)
  • Heat sensitivities
  • Thinning skin
  • Hair loss or brittle hair
  • Frequent bowel movements
  • Changes in menstrual cycles, including missed periods
  • Muscle weakness, most notably in your thighs and upper arms

  • Blurry vision
  • Bulging or protruding eyes
Overall, the symptoms of hyperthyroidism are similar in children and adults.

Learn More About the Signs and Symptoms of Hyperthyroidism

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, also known as thyroid eye disease, 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.

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

Common Medications That Can Lead to Thyroid Dysfunction

Aside from overtreatment of hypothyroidism with thyroxine, other medications may also increase your risk of hyperthyroidism.

These include:
Taking a biotin supplement does not cause thyroid dysfunction, but it may lead to false-positive hyperthyroid lab results. Too much biotin, exceeding the recommended 30 micrograms (mcg) per day, may lead to an incorrect hyperthyroid diagnosis because your labs may show artificially high T3 and T4 hormones and low TSH. Doctors usually recommend holding off on biotin supplements for four to six days before having thyroid labs done.

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.

Prognosis of Hyperthyroidism

In general, hyperthyroidism progresses slowly, but the rate can be different in younger people. This age group may see their symptoms develop quickly.

Once you have hyperthyroidism, you will need to check your thyroid levels regularly. This ensures your thyroid gland is releasing the right amount of hormone. In some cases, treating hyperthyroidism could lead to hypothyroidism. With proper treatment, you can restore your thyroid to normal function.

It’s important to see your doctor if any new symptoms arise, and to follow your treatment plan as prescribed. According to a study, the duration of untreated (and undertreated) hyperthyroidism increased the risk of cardiovascular disease in patients with an overactive thyroid.

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.

Treatment and Medication for Hyperthyroidism

An overactive thyroid gland is more difficult to control than an underactive one. With the latter, treatment usually involves taking hormones to make up for the missing amounts. But it can be more challenging to stop the thyroid gland from making too much hormone, as seen in hyperthyroidism.

Your overall treatment plan may depend on your age and the severity of your condition. The following treatments are effective for hyperthyroidism.

Medication Options

Anti-thyroid drugs are often the first treatment measure for hyperthyroidism caused by excess thyroid, especially in children. The purpose of anti-thyroid drugs is to stop the thyroid gland from making too much hormone. You may take these medicines for at least a year, and it may take a few weeks to months for your symptoms to start improving. Examples of anti-thyroid drugs include methimazole (Tapazole) and propylthiouracil.

Another method to treat hyperthyroidism caused by excess thyroid production is to take radioactive iodine. It’s taken by mouth, and it shrinks the thyroid gland to eliminate overactive cells. As with anti-thyroid drugs, it can take at least a few months for radioactive iodine’s effects to kick in. You may develop hypothyroidism as a side effect. If this is the case, you will need to take thyroid hormone replacements such as levothyroxine (Synthroid).

In some cases, your doctor may prescribe beta-blockers to alleviate hyperthyroid symptoms such as hypertension, increased heart rate, palpitations, and tremors. These medications don’t actually treat hyperthyroidism itself, so your doctor may recommend easing off beta-blockers once your thyroid levels improve.

Surgery Options

A thyroidectomy is a type of surgery that is used to remove the thyroid gland in an effort to treat hyperthyroidism caused by excessive production of thyroid. With a partial thyroidectomy, one half or a small portion is removed. A total thyroidectomy can result in permanent hypothyroidism, for which you’ll need to take hormone replacements for life. In total thyroidectomy, your surgeon will make every attempt to preserve the parathyroid glands, which produce a hormone that helps regulate calcium in the blood. If your surgeon does have to remove these glands, you may also need to take calcium supplements.

Over-the-Counter Options

Some people with Graves’ disease end up developing Graves’ ophthalmopathy (thyroid eye disease), which affects the eyes. Controlling Graves’ disease can also help control eye symptoms, but other treatments may be used, too. These include artificial tears to relieve dry eyes, corticosteroids to reduce eye inflammation, and radiation for swelling or vision loss. Surgery is another possibility, including bone and muscle surgeries. The goal of Graves’ ophthalmopathy treatment is to reduce eye symptoms while also preventing complications, such as vision loss.

Integrative and Complementary Approaches

While DIY natural home remedies are often touted for thyroid disease treatment, supplements, herbs, and the like don’t work to treat an overactive thyroid. In some cases, as with iodine, these approaches may do more harm than good.

Learn More About Treatment for Hyperthyroidism: Medication, Alternative and Complementary Therapies, Surgery Options, and More

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

Prevention of Hyperthyroidism

Hyperthyroidism isn’t a preventable condition. If Graves’ disease runs in your family, you have a greater risk of developing an overactive thyroid gland and requiring long-term treatment.

If you develop hyperthyroidism during or after a pregnancy, your condition may last for a few months and you may subsequently develop hypothyroidism.

It’s important to focus on your individual risk factors for hyperthyroidism and to see your doctor for a blood test if needed.

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:

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 (thyroid eye disease) 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.

Research and Statistics: Who Has Hyperthyroidism?

About 1 in 100 people in the United States has overactive thyroid.

Hyperthyroidism in women is more common than in men, but anyone can develop the condition.

Women who have been pregnant in the last six months are at a higher risk for hyperthyroidism. This is primarily caused by postpartum thyroiditis.

Hyperthyroidism is more prevalent in people over the age of 60, especially women.

Graves’ disease — an autoimmune disorder that’s the most common cause of hyperthyroidism — affects an estimated 1 out of 10,000 children in the United States.

Graves’ disease also runs in families.

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:

Hyperthyroidism Resources We Love

Favorite Organizations for Essential Hyperthyroidism Info

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 its 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.

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.

Favorite Integrative Sources for Hyperthyroidism

American Thyroid Association

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

Drugs.com

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 and 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 Health Publishing

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.

EndocrineWeb

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

Favorite Hyperthyroidism Apps

Breathe2Relax

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.

Editorial Sources and Fact-Checking

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