Factitious hyperthyroidism
Factitious thyrotoxicosis; Thyrotoxicosis factitia; Thyrotoxicosis medicamentosa; Factitious hyperthyroxinemiaFactitious hyperthyroidism is higher-than-normal thyroid hormone levels in the blood and symptoms that suggest hyperthyroidism. It occurs from taking too much thyroid hormone medicine.
Hyperthyroidism is also known as overactive thyroid.
Causes
The thyroid gland produces the hormones thyroxine (T4) and triiodothyronine (T3). In most cases of hyperthyroidism, the thyroid gland itself produces too much of these hormones.
Hyperthyroidism
Hyperthyroidism is a condition in which the thyroid gland makes too much thyroid hormone. The condition is often called overactive thyroid.
Read Article Now Book Mark ArticleHyperthyroidism can also be caused by taking too much thyroid hormone medicine for hypothyroidism. This is called factitious hyperthyroidism. When this occurs because the prescribed dosage of hormone medicine is too high, it is called iatrogenic, or doctor-induced, hyperthyroidism. This is common. Sometimes this is intentional (for some people with depression or thyroid cancer), but often this happens because the dose is not adjusted based on follow-up blood tests.
Hypothyroidism
Hypothyroidism is a condition in which the thyroid gland does not make enough thyroid hormone. This condition is often called underactive thyroid....
Read Article Now Book Mark ArticleFactitious hyperthyroidism can also occur when someone takes too much thyroid hormone on purpose and may conceal this. This is very uncommon. These may be people:
- Who have mental disorders such as Munchausen syndrome
Munchausen syndrome
Munchausen syndrome by proxy is a mental illness and a form of child abuse. The caretaker of a child, most often a mother, either makes up fake symp...
Read Article Now Book Mark Article - Who are trying to lose weight
- Who are being treated for depression or infertility
Children may take thyroid hormone pills accidentally.
Symptoms
The symptoms of factitious hyperthyroidism are the same as those of hyperthyroidism caused by a thyroid gland disorder, except that:
- There is no goiter. The thyroid gland is often small.
Goiter
A simple goiter is an enlargement of the thyroid gland. It is usually not a tumor or cancer.
Read Article Now Book Mark Article - The eyes do not bulge, as they do in Graves disease (the most common type of hyperthyroidism).
Graves disease
Graves disease is an autoimmune disorder that leads to an overactive thyroid gland (hyperthyroidism). An autoimmune disorder is a condition that occ...
Read Article Now Book Mark Article - The skin over the shins does not thicken, as it sometimes does in people who have Graves disease.
Exams and Tests
Blood tests used to diagnose factitious hyperthyroidism include:
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Free T4
Free T4
T4 (thyroxine) is the main hormone produced by the thyroid gland. A laboratory test can be done to measure the amount of free T4 in your blood. Fre...
Read Article Now Book Mark Article - Thyroglobulin
- Total T3
T3
Triiodothyronine (T3) is a thyroid hormone. It plays an important role in the body's control of metabolism (the many processes that control the rate...
Read Article Now Book Mark Article - Total T4
T4
T4 (thyroxine) is the main hormone produced by the thyroid gland. A laboratory test can be done to measure the amount of free T4 in your blood. Fre...
Read Article Now Book Mark Article -
TSH
TSH
A 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...
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Other tests that may be done include radioactive iodine uptake or thyroid ultrasound.
Radioactive iodine uptake
Radioactive iodine uptake (RAIU) tests thyroid function. It measures how much radioactive iodine is taken up by your thyroid gland in a certain time...
Read Article Now Book Mark ArticleTreatment
Your health care provider will tell you to stop taking thyroid hormone. If you need to take it, your provider will reduce the dosage.
You should be re-checked in 2 to 4 weeks to be sure that the signs and symptoms are gone. This also helps to confirm the diagnosis.
People with Munchausen syndrome will need mental health treatment and follow up.
Outlook (Prognosis)
Factitious hyperthyroidism will resolve on its own when you stop taking or lower the dosage of thyroid hormone.
Possible Complications
When factitious hyperthyroidism lasts a long time, the same complications as untreated or poorly treated hyperthyroidism may develop:
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Abnormal heartbeat (atrial fibrillation)
Atrial fibrillation
Atrial fibrillation (Afib) and atrial flutter are common types of abnormal heart rhythms (arrhythmias) which affect the upper chambers (atria) of the...
Read Article Now Book Mark Article - Anxiety
-
Chest pain (angina)
Chest pain
Chest pain is discomfort or pain that you feel anywhere along the front of your body between your neck and upper abdomen.
Read Article Now Book Mark ArticleAngina
Angina is a type of chest discomfort or pain due to poor blood flow through the blood vessels (coronary vessels) of the heart muscle (myocardium). T...
Read Article Now Book Mark Article -
Heart attack
Heart attack
Most heart attacks are caused by a blood clot that blocks one of the coronary arteries. The coronary arteries bring blood and oxygen to the heart. ...
Read Article Now Book Mark Article - Loss of bone mass (if severe, osteoporosis)
Osteoporosis
Osteoporosis is a disease in which bones become fragile and more likely to break (fracture).
Read Article Now Book Mark Article -
Weight loss
Weight loss
Unexplained 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 - Infertility
- Problems sleeping
When to Contact a Medical Professional
Contact your provider if you have symptoms of hyperthyroidism.
Prevention
Thyroid hormone should be taken only by prescription and under the supervision of a provider. Regular blood tests are often needed to help your provider adjust the dose you are taking.
References
Jonklaas J. Hypothyroidism. In: Robertson RP, ed. DeGroot's Endocrinology. 8th ed. Philadelphia, PA: Elsevier; 2023:chap 74.
Pearce EN, Hollenberg AN. Thyroid. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 207.
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Thyroid gland - illustration
The thyroid gland, a part of the endocrine (hormone) system, plays a major role in regulating the body's metabolism.
Thyroid gland
illustration
Review Date: 5/20/2024
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.