BACK TOTOP Browse A-ZSearchBrowse A-ZABCDEFGHIJKLMNOPQRSTUVWXYZ0-9 E-mail FormEmail ResultsName:Email address:Recipients Name:Recipients address:Message: Print-FriendlyBookmarksbookmarks-menuHyperthyroidismThyrotoxicosis; Overactive thyroid; Graves disease - hyperthyroidism; Thyroiditis - hyperthyroidism; Toxic goiter - hyperthyroidism; Thyroid nodules - hyperthyroidism; Thyroid hormone - hyperthyroidismHyperthyroidism is a condition in which the thyroid gland makes too much thyroid hormone. The condition is often called overactive thyroid.Related video goes here for no-HTML5 browsers Causes The thyroid gland is an important organ of the endocrine system. It is located at the front of the neck just above where your collarbones meet. The gland makes the hormones that control the way every cell in the body uses energy. This process is called metabolism.EndocrineEndocrine glands release (secrete) hormones into the bloodstream. The endocrine glands include the:AdrenalHypothalamusIslets of Langerhans in the pan...ImageRead Article Now Book Mark Article MetabolismMetabolism refers to all the physical and chemical processes in the body that convert or use energy, such as:BreathingCirculating bloodControlling bo...ImageRead Article Now Book Mark Article Previous imagePlay SlideshowStop SlideshowNext image / Many diseases and conditions can cause hyperthyroidism, including:Graves disease (most common cause of hyperthyroidism) Graves diseaseGraves disease is an autoimmune disorder that leads to an overactive thyroid gland (hyperthyroidism). An autoimmune disorder is a condition that occ...ImageRead Article Now Book Mark Article Inflammation (thyroiditis) of the thyroid due to viral infections, some medicines, or after pregnancy (common) Taking too much thyroid hormone (common) Noncancerous growths of the thyroid gland or pituitary gland (rare) Some tumors of the testes or ovaries (rare) TestesThe testes are 2 egg-shaped male reproductive organs located in the scrotum. They produce sperm and the male hormone, testosterone.ImageRead Article Now Book Mark Article Getting medical imaging tests with contrast dye that has iodine (rare, and only if there is already a problem with the thyroid) Eating too much of foods that contain iodine (very rare, and only if there is already a problem with the thyroid) Previous imagePlay SlideshowStop SlideshowNext image / Symptoms Common symptoms include:Anxiety Difficulty concentrating Fatigue FatigueFatigue is a feeling of weariness, tiredness, or lack of energy.ImageRead Article Now Book Mark Article Frequent bowel movements Goiter (visibly enlarged thyroid gland) or thyroid nodules GoiterA simple goiter is an enlargement of the thyroid gland. It is usually not a tumor or cancer.ImageRead Article Now Book Mark Article Thyroid nodulesA thyroid nodule is a growth (lump) in the thyroid gland. The thyroid gland is located at the front of the neck, just above where your collarbones m...ImageRead Article Now Book Mark Article Hair loss Hand tremor Hand tremorA tremor is a type of shaking movement. A tremor is most often noticed in the hands and arms. It may affect any body part, including the head, tong...ImageRead Article Now Book Mark Article Heat intolerance Heat intoleranceHeat intolerance is a feeling of being overheated when the temperature around you rises. It can often cause heavy sweating. Heat intolerance usually...ImageRead Article Now Book Mark Article Increased appetite Increased appetiteIncreased appetite means you have an excess desire for food.ImageRead Article Now Book Mark Article Increased sweating Increased sweatingSweating is the release of liquid from the body's sweat glands. This liquid contains salt. This process is also called perspiration. Sweating helps...ImageRead Article Now Book Mark Article Irregular menstrual periods in women Nail changes (thickness or flaking) Nervousness Pounding or racing heart beat (palpitations) PalpitationsPalpitations are feelings or sensations that your heart is pounding or racing. They can be felt in your chest, throat, or neck. You may:Have an unpl...ImageRead Article Now Book Mark Article Restlessness RestlessnessAgitation is an unpleasant state of extreme arousal. An agitated person may feel stirred up, excited, tense, confused, or irritable.Read Article Now Book Mark Article Sleep problems Weight loss (or weight gain, in some cases) Weight lossUnexplained weight loss is a decrease in body weight, when you did not try to lose the weight on your own. Many people gain and lose weight. Uninten...Read Article Now Book Mark Article Previous imagePlay SlideshowStop SlideshowNext image / Other symptoms that can occur with this condition:Breast development in men Clammy skin Diarrhea Feeling faint when you raise your hands High blood pressure High blood pressureBlood pressure is a measurement of the force exerted against the walls of your arteries as your heart pumps blood to your body. Hypertension is the ...ImageRead Article Now Book Mark Article Itchy or irritated eyes Itchy skin Nausea and vomiting Protruding eyes (exophthalmos) Protruding eyesBulging eyes is the abnormal protrusion (bulging out) of one or both eyeballs.ImageRead Article Now Book Mark Article Skin blushing or flushing Skin rash on the shins Weakness of the hips and shoulders WeaknessWeakness is reduced strength in one or more muscles.ImageRead Article Now Book Mark Article Previous imagePlay SlideshowStop SlideshowNext image / Exams and Tests The health care provider will do a physical exam. The exam may find the following:High systolic blood pressure (the first number in a blood pressure reading) Increased heart rate Heart rateThe pulse is the number of heartbeats per minute.ImageRead Article Now Book Mark Article Enlarged thyroid gland Shaking of the hands Swelling or inflammation around the eyes Very strong reflexes ReflexesA reflex is a muscle reaction that happens automatically in response to stimulation. Certain sensations or movements produce specific muscle respons...ImageRead Article Now Book Mark Article Skin, hair, and nail changesBlood tests are also ordered to measure your thyroid hormones (free thyroxine or free T4 and triiodothyronine or T3) and a pituitary hormone that regulates the thyroid gland (thyroid stimulating hormone or TSH).TSHA TSH test measures the amount of thyroid stimulating hormone (TSH) in your blood. TSH is produced by the pituitary gland. It prompts the thyroid g...ImageRead Article Now Book Mark Article You may also have blood tests to check:Cholesterol levels Glucose GlucoseA blood sugar test measures the amount of sugar (glucose) in a sample of your blood. Glucose is a major source of energy for most cells of the body, ...ImageRead Article Now Book Mark Article Specialized thyroid tests like Thyroid receptor antibody (TRAb) or Thyroid Stimulating Immunoglobulin (TSI)Thyroid Stimulating Immunoglobulin (TSITSI stands for thyroid stimulating immunoglobulin. TSIs are antibodies that tell the thyroid gland to become more active and release excess amounts ...ImageRead Article Now Book Mark Article Imaging tests of the thyroid may also be needed, including:Radioactive iodine uptake and scan Radioactive iodine uptake and scanRadioactive iodine uptake (RAIU) tests thyroid function. It measures how much radioactive iodine is taken up by your thyroid gland in a certain time...ImageRead Article Now Book Mark Article Thyroid ultrasound (rarely)Thyroid ultrasoundA thyroid ultrasound is an imaging method to see the thyroid, a gland in the neck that regulates metabolism (the many processes that control the rate...ImageRead Article Now Book Mark Article Treatment Treatment depends on the cause and severity of symptoms. Hyperthyroidism is usually treated with one or more of the following:Antithyroid medicines (propylthiouracil or methimazole) which reduce or block the effects of the extra thyroid hormone Radioactive iodine to destroy the thyroid gland and stop the excess production of hormones Surgery to remove the thyroid If your thyroid is removed with surgery or destroyed with radioactive iodine, you must take thyroid hormone replacement pills for the rest of your life.Medicines called beta-blockers may be prescribed to treat symptoms such as fast heart rate, tremor, sweating, and anxiety until the hyperthyroidism can be controlled. Outlook (Prognosis) Hyperthyroidism is treatable. Some causes, such as thyroiditis, may go away without treatment.Hyperthyroidism caused by Graves disease usually gets worse over time. It has many complications, some of which are severe and affect quality of life. Possible Complications Thyroid crisis (also called thyroid storm) is a sudden worsening of hyperthyroidism symptoms that may occur with infection or stress. Fever, decreased alertness, and abdominal pain may occur. People need to be treated in the hospital.Other complications of hyperthyroidism include:Heart problems such as fast heart rate, abnormal heart rhythm, and heart failure Osteoporosis Eye disease (double vision, ulcers of the cornea, vision loss)Surgery-related complications, including: Scarring of the neck Hoarseness due to nerve damage to the voice box Low calcium level due to damage to the parathyroid glands (located near the thyroid gland) Hypothyroidism (underactive thyroid)HypothyroidismHypothyroidism is a condition in which the thyroid gland does not make enough thyroid hormone. This condition is often called underactive thyroid....ImageRead Article Now Book Mark Article Tobacco use may make some complications of hyperthyroidism worse. When to Contact a Medical Professional Contact your provider if you have symptoms of hyperthyroidism. Go to an emergency room or call 911 or the local emergency number if you have:Change in consciousness Dizziness Rapid, irregular heartbeatRapid, irregular heartbeatAn arrhythmia is a disorder of the heart rate (pulse) or heart rhythm. The heart can beat too fast (tachycardia), too slow (bradycardia), or irregul...ImageRead Article Now Book Mark Article Contact your provider if you are being treated for hyperthyroidism and you develop symptoms of underactive thyroid, including:Depression DepressionDepression may be described as feeling sad, blue, unhappy, miserable, or down in the dumps. Most of us feel this way at one time or another for shor...ImageRead Article Now Book Mark Article Mental and physical sluggishness Weight gain Open ReferencesReferencesHollenberg A, Wiersinga W, Bartalena L, Feldt-Rasmussen U. Hyperthyroid disorders. In: Melmed S, Auchus RJ, Goldfine AB, Rosen CJ, Kopp PA, eds. Williams Textbook of Endocrinology. 15th ed. Philadelphia, PA: Elsevier; 2025:chap 10.Pearce EN, Hollenberg AN. Thyroid. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 207.Ross DS, Burch HB, Cooper DS, et al. 2016 American Thyroid Association guidelines for diagnosis and management of hyperthyroidism and other causes of thyrotoxicosis. Thyroid. 2016;26(10):1343-1421. PMID: 27521067 pubmed.ncbi.nlm.nih.gov/27521067/.AllVideoImagesTogEndocrine glands - illustration Endocrine glands release hormones (chemical messengers) into the bloodstream to be transported to various organs and tissues throughout the body. For instance, the pancreas secretes insulin, which allows the body to regulate levels of sugar in the blood. The thyroid gets instructions from the pituitary to secrete hormones which determine the rate of metabolism in the body (the more hormone in the bloodstream, the faster the chemical activity; the less hormone, the slower the activity).Endocrine glandsillustrationGoiter - illustration A goiter is a swelling in the neck due to an enlarged thyroid gland. The size may range from a single small nodule to a large neck lump. The swollen thyroid can put pressure on the windpipe and esophagus which can cause a cough, wheezing, breathing difficulties or swallowing difficulties. A goiter only needs to be treated if it is causing symptoms.GoiterillustrationBrain-thyroid link - illustration Although the thyroid gland releases the hormones which govern growth and metabolism, the brain (the pituitary and the hypothalamus) manages the release and the balance of the amount of hormones circulated.Brain-thyroid linkillustrationThyroid gland - illustration The thyroid gland, a part of the endocrine (hormone) system, plays a major role in regulating the body's metabolism.Thyroid glandillustrationEndocrine glands - illustration Endocrine glands release hormones (chemical messengers) into the bloodstream to be transported to various organs and tissues throughout the body. For instance, the pancreas secretes insulin, which allows the body to regulate levels of sugar in the blood. The thyroid gets instructions from the pituitary to secrete hormones which determine the rate of metabolism in the body (the more hormone in the bloodstream, the faster the chemical activity; the less hormone, the slower the activity).Endocrine glandsillustrationGoiter - illustration A goiter is a swelling in the neck due to an enlarged thyroid gland. The size may range from a single small nodule to a large neck lump. The swollen thyroid can put pressure on the windpipe and esophagus which can cause a cough, wheezing, breathing difficulties or swallowing difficulties. A goiter only needs to be treated if it is causing symptoms.GoiterillustrationBrain-thyroid link - illustration Although the thyroid gland releases the hormones which govern growth and metabolism, the brain (the pituitary and the hypothalamus) manages the release and the balance of the amount of hormones circulated.Brain-thyroid linkillustrationThyroid gland - illustration The thyroid gland, a part of the endocrine (hormone) system, plays a major role in regulating the body's metabolism.Thyroid glandillustrationRelated Information Metabolism(Special Topic)Endocrine glands(Special Topic)Testes(Special Topic)Silent thyroiditis(Condition)Factitious hyperthyroidism(Condition)Hypothyroidism(Condition)Graves disease(Condition)Pulse - bounding(Symptoms)Atrial fibrillation and atrial flutter(Condition)Fever(Symptoms)Thyroid gland removal - discharge(Discharge)Hypothyroidism - InDepth(In-Depth) Review Date: 7/21/2024 Reviewed By: Sandeep K. Dhaliwal, MD, board-certified in Diabetes, Endocrinology, and Metabolism, Springfield, VA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. No warranty of any kind, either expressed or implied, is made as to the accuracy, reliability, timeliness, or correctness of any translations made by a third-party service of the information provided herein into any other language. © 1997- A.D.A.M., a business unit of Ebix, Inc. Any duplication or distribution of the information contained herein is strictly prohibited. © 1997- All rights reserved. A.D.A.M. content is best viewed in IE9 or above, Firefox and Google Chrome browser.Content is best viewed in IE9 or above, Firefox and Google Chrome browser.
HyperthyroidismThyrotoxicosis; Overactive thyroid; Graves disease - hyperthyroidism; Thyroiditis - hyperthyroidism; Toxic goiter - hyperthyroidism; Thyroid nodules - hyperthyroidism; Thyroid hormone - hyperthyroidismHyperthyroidism is a condition in which the thyroid gland makes too much thyroid hormone. The condition is often called overactive thyroid.Related video goes here for no-HTML5 browsers Causes The thyroid gland is an important organ of the endocrine system. It is located at the front of the neck just above where your collarbones meet. The gland makes the hormones that control the way every cell in the body uses energy. This process is called metabolism.EndocrineEndocrine glands release (secrete) hormones into the bloodstream. The endocrine glands include the:AdrenalHypothalamusIslets of Langerhans in the pan...ImageRead Article Now Book Mark Article MetabolismMetabolism refers to all the physical and chemical processes in the body that convert or use energy, such as:BreathingCirculating bloodControlling bo...ImageRead Article Now Book Mark Article Previous imagePlay SlideshowStop SlideshowNext image / Many diseases and conditions can cause hyperthyroidism, including:Graves disease (most common cause of hyperthyroidism) Graves diseaseGraves disease is an autoimmune disorder that leads to an overactive thyroid gland (hyperthyroidism). An autoimmune disorder is a condition that occ...ImageRead Article Now Book Mark Article Inflammation (thyroiditis) of the thyroid due to viral infections, some medicines, or after pregnancy (common) Taking too much thyroid hormone (common) Noncancerous growths of the thyroid gland or pituitary gland (rare) Some tumors of the testes or ovaries (rare) TestesThe testes are 2 egg-shaped male reproductive organs located in the scrotum. They produce sperm and the male hormone, testosterone.ImageRead Article Now Book Mark Article Getting medical imaging tests with contrast dye that has iodine (rare, and only if there is already a problem with the thyroid) Eating too much of foods that contain iodine (very rare, and only if there is already a problem with the thyroid) Previous imagePlay SlideshowStop SlideshowNext image / Symptoms Common symptoms include:Anxiety Difficulty concentrating Fatigue FatigueFatigue is a feeling of weariness, tiredness, or lack of energy.ImageRead Article Now Book Mark Article Frequent bowel movements Goiter (visibly enlarged thyroid gland) or thyroid nodules GoiterA simple goiter is an enlargement of the thyroid gland. It is usually not a tumor or cancer.ImageRead Article Now Book Mark Article Thyroid nodulesA thyroid nodule is a growth (lump) in the thyroid gland. The thyroid gland is located at the front of the neck, just above where your collarbones m...ImageRead Article Now Book Mark Article Hair loss Hand tremor Hand tremorA tremor is a type of shaking movement. A tremor is most often noticed in the hands and arms. It may affect any body part, including the head, tong...ImageRead Article Now Book Mark Article Heat intolerance Heat intoleranceHeat intolerance is a feeling of being overheated when the temperature around you rises. It can often cause heavy sweating. Heat intolerance usually...ImageRead Article Now Book Mark Article Increased appetite Increased appetiteIncreased appetite means you have an excess desire for food.ImageRead Article Now Book Mark Article Increased sweating Increased sweatingSweating is the release of liquid from the body's sweat glands. This liquid contains salt. This process is also called perspiration. Sweating helps...ImageRead Article Now Book Mark Article Irregular menstrual periods in women Nail changes (thickness or flaking) Nervousness Pounding or racing heart beat (palpitations) PalpitationsPalpitations are feelings or sensations that your heart is pounding or racing. They can be felt in your chest, throat, or neck. You may:Have an unpl...ImageRead Article Now Book Mark Article Restlessness RestlessnessAgitation is an unpleasant state of extreme arousal. An agitated person may feel stirred up, excited, tense, confused, or irritable.Read Article Now Book Mark Article Sleep problems Weight loss (or weight gain, in some cases) Weight lossUnexplained weight loss is a decrease in body weight, when you did not try to lose the weight on your own. Many people gain and lose weight. Uninten...Read Article Now Book Mark Article Previous imagePlay SlideshowStop SlideshowNext image / Other symptoms that can occur with this condition:Breast development in men Clammy skin Diarrhea Feeling faint when you raise your hands High blood pressure High blood pressureBlood pressure is a measurement of the force exerted against the walls of your arteries as your heart pumps blood to your body. Hypertension is the ...ImageRead Article Now Book Mark Article Itchy or irritated eyes Itchy skin Nausea and vomiting Protruding eyes (exophthalmos) Protruding eyesBulging eyes is the abnormal protrusion (bulging out) of one or both eyeballs.ImageRead Article Now Book Mark Article Skin blushing or flushing Skin rash on the shins Weakness of the hips and shoulders WeaknessWeakness is reduced strength in one or more muscles.ImageRead Article Now Book Mark Article Previous imagePlay SlideshowStop SlideshowNext image / Exams and Tests The health care provider will do a physical exam. The exam may find the following:High systolic blood pressure (the first number in a blood pressure reading) Increased heart rate Heart rateThe pulse is the number of heartbeats per minute.ImageRead Article Now Book Mark Article Enlarged thyroid gland Shaking of the hands Swelling or inflammation around the eyes Very strong reflexes ReflexesA reflex is a muscle reaction that happens automatically in response to stimulation. Certain sensations or movements produce specific muscle respons...ImageRead Article Now Book Mark Article Skin, hair, and nail changesBlood tests are also ordered to measure your thyroid hormones (free thyroxine or free T4 and triiodothyronine or T3) and a pituitary hormone that regulates the thyroid gland (thyroid stimulating hormone or TSH).TSHA TSH test measures the amount of thyroid stimulating hormone (TSH) in your blood. TSH is produced by the pituitary gland. It prompts the thyroid g...ImageRead Article Now Book Mark Article You may also have blood tests to check:Cholesterol levels Glucose GlucoseA blood sugar test measures the amount of sugar (glucose) in a sample of your blood. Glucose is a major source of energy for most cells of the body, ...ImageRead Article Now Book Mark Article Specialized thyroid tests like Thyroid receptor antibody (TRAb) or Thyroid Stimulating Immunoglobulin (TSI)Thyroid Stimulating Immunoglobulin (TSITSI stands for thyroid stimulating immunoglobulin. TSIs are antibodies that tell the thyroid gland to become more active and release excess amounts ...ImageRead Article Now Book Mark Article Imaging tests of the thyroid may also be needed, including:Radioactive iodine uptake and scan Radioactive iodine uptake and scanRadioactive iodine uptake (RAIU) tests thyroid function. It measures how much radioactive iodine is taken up by your thyroid gland in a certain time...ImageRead Article Now Book Mark Article Thyroid ultrasound (rarely)Thyroid ultrasoundA thyroid ultrasound is an imaging method to see the thyroid, a gland in the neck that regulates metabolism (the many processes that control the rate...ImageRead Article Now Book Mark Article Treatment Treatment depends on the cause and severity of symptoms. Hyperthyroidism is usually treated with one or more of the following:Antithyroid medicines (propylthiouracil or methimazole) which reduce or block the effects of the extra thyroid hormone Radioactive iodine to destroy the thyroid gland and stop the excess production of hormones Surgery to remove the thyroid If your thyroid is removed with surgery or destroyed with radioactive iodine, you must take thyroid hormone replacement pills for the rest of your life.Medicines called beta-blockers may be prescribed to treat symptoms such as fast heart rate, tremor, sweating, and anxiety until the hyperthyroidism can be controlled. Outlook (Prognosis) Hyperthyroidism is treatable. Some causes, such as thyroiditis, may go away without treatment.Hyperthyroidism caused by Graves disease usually gets worse over time. It has many complications, some of which are severe and affect quality of life. Possible Complications Thyroid crisis (also called thyroid storm) is a sudden worsening of hyperthyroidism symptoms that may occur with infection or stress. Fever, decreased alertness, and abdominal pain may occur. People need to be treated in the hospital.Other complications of hyperthyroidism include:Heart problems such as fast heart rate, abnormal heart rhythm, and heart failure Osteoporosis Eye disease (double vision, ulcers of the cornea, vision loss)Surgery-related complications, including: Scarring of the neck Hoarseness due to nerve damage to the voice box Low calcium level due to damage to the parathyroid glands (located near the thyroid gland) Hypothyroidism (underactive thyroid)HypothyroidismHypothyroidism is a condition in which the thyroid gland does not make enough thyroid hormone. This condition is often called underactive thyroid....ImageRead Article Now Book Mark Article Tobacco use may make some complications of hyperthyroidism worse. When to Contact a Medical Professional Contact your provider if you have symptoms of hyperthyroidism. Go to an emergency room or call 911 or the local emergency number if you have:Change in consciousness Dizziness Rapid, irregular heartbeatRapid, irregular heartbeatAn arrhythmia is a disorder of the heart rate (pulse) or heart rhythm. The heart can beat too fast (tachycardia), too slow (bradycardia), or irregul...ImageRead Article Now Book Mark Article Contact your provider if you are being treated for hyperthyroidism and you develop symptoms of underactive thyroid, including:Depression DepressionDepression may be described as feeling sad, blue, unhappy, miserable, or down in the dumps. Most of us feel this way at one time or another for shor...ImageRead Article Now Book Mark Article Mental and physical sluggishness Weight gain Open ReferencesReferencesHollenberg A, Wiersinga W, Bartalena L, Feldt-Rasmussen U. Hyperthyroid disorders. In: Melmed S, Auchus RJ, Goldfine AB, Rosen CJ, Kopp PA, eds. Williams Textbook of Endocrinology. 15th ed. Philadelphia, PA: Elsevier; 2025:chap 10.Pearce EN, Hollenberg AN. Thyroid. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 207.Ross DS, Burch HB, Cooper DS, et al. 2016 American Thyroid Association guidelines for diagnosis and management of hyperthyroidism and other causes of thyrotoxicosis. Thyroid. 2016;26(10):1343-1421. PMID: 27521067 pubmed.ncbi.nlm.nih.gov/27521067/.
