Sandbox: hyperthyroidism landing

Template:Hyperthyroidism landing Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1];Associate Editor(s)-in-Chief: Ahmed Younes M.B.B.CH [2]

Patient information

Overview

Hyperthyroidism is a disorder that the thyroid gland makes too much thyroid hormone. About 1 percent of the U.S. population has hyperthyroidism. Some diseases, such as Graves’ disease, thyroid nodules and thyroiditis, are associated with the cause of hyperthyroidism. Hyperthyroidism can affect your metabolism. Usual signs and symptoms include goiter, increased appetite but weight loss, palpitation, hypertension, increased sensitivity to heat and perspiration, nervousness and hand tremors. The Thyroid-Stimulating Hormone (TSH) test is a very sensitive and useful test to identify the disorder. Other examinations include the T3 and T4 test, radioactive iodine uptake test and thyroid scan. Treatment options of hyperthyroidism depend on the cause, age, physical condition and the severity of symptoms. Usual treatment measures are medications, radioactive iodine and thyroidectomy. The common side effect of radioactive iodine and thyroidectomy is hypothyroidism. The patient will need to take thyroid hormone supplement to restore normal hormone levels.

What are the symptoms of Hyperthyroidism?

Symptoms of hyperthyroidism vary from person to person. Usual signs include the following:

• Goiter
• Increased appetite, but weight loss
• Palpitation
• Hypertension
• Increased sensitivity to heat and perspiration
• Nervousness, anxiety or irritability, difficulty sleeping
• Hand tremors
• Fatigue, muscle weakness
• Changes in menstrual patterns (usually lighter flow, less frequent periods) in women

Other health problems may also cause these symptoms. Only a doctor can tell for sure. A person with any of these symptoms should tell the doctor so that the problems can be diagnosed and treated as early as possible.

Who is at highest risk?

• Graves’ disease
• Thyroid nodules
• Thyroiditis
• Too much iodine ingestion
• Over-medicating with synthetic thyroid hormone

Diagnosis

• Thyroid-Stimulating Hormone (TSH) test: This is a very sensitive and useful test and usually used as the first test to identify the disorder. The TSH test is based on the feedback between TSH and thyroid hormone. Patients with hyperthyroidism may show a lower reading than normal people.
• T3 and T4 test: This test may show the levels of T3 and T4 in your blood. In patients with hyperthyroidism, the levels of one or both of these hormones in your blood will be higher than normal.
• Thyroid-stimulating immunoglobulin (TSI) test: This test may help diagnose Graves' disease, which has this kind of antibody.
• Radioactive iodine uptake test: This test can detect the iodine uptake function of your thyroid gland and help diagnose the cause of hyperthyroidism. For example, low levels of iodine uptake might be a sign of thyroiditis, whereas high levels could indicate Graves’ disease.
• Thyroid scan: This test may also help diagnose the cause of hyperthyroidism by providing images of nodules and other possible thyroid irregularities.

Other diseases with similar symptoms:

• Autonomic nerve dysfunction
• Coronary artery disease
• Goiter
• Schizophrenia
• Thyroid cancer

When to seek urgent medical care?

Call your health care provider if symptoms of hyperthyroidism develop. If you experience either of the following symptoms, seeking urgent medical care as soon as possible:

• Palpitation
• Severe hypertension

Treatment options

Usual treatment measures of hyperthyroidism include medications, radioactive iodine, and surgery. Treatment options depend on the cause, age, physical condition and the severity of symptoms.

• Medications: Antithyroid medications, such as methimazole (Tapazole) and propylthiouracil (PTU), are used to block the production of thyroid hormone. Symptoms may begin to improve in 6 to 12 weeks and the whole treatment period may last for at least a year. Beta blockers, for example propranolol, may be used to relieve symptoms such as palpitation, nervousness,hypertension, sweating and shaking.
• Radioactive iodine: This kind of treatment may destroy the thyroid gland and stop the excess production of hormones. During this period, the patient takes radioactive iodine by mouth. A common side effect is permanent hypothyroidism, which needs thyroid supplements.
• Surgery: Thyroidectomy is another type of treatment option. The possible side effect after surgery is hypothyroidism. Patients need to take thyroid hormone supplements to restore normal hormone levels.

Contraindicated medications

Patients diagnosed with hyperthyroidism should avoid using the following medications:

• Levothyroxine
• Phentermine
  If you have been diagnosed with hyperthyroidism, consult your physician before starting or stopping any of these medications.

Where to find medical care for Hyperthyroidism?

Directions to Hospitals Treating Hyperthyroidism

Prevention

• For hyperthyroidism caused by too much iodine ingestion, the method of prevention is decreasing iodine ingestion and a regular check of thyroid hormone levels in the blood.
• For hyperthyroidism caused by over-medicating with synthetic thyroid hormone, giving the appropriate dose to patients and a regular check of thyroid hormone levels in the blood may be important.

What to expect (Outlook/Prognosis)?

Many cases of hyperthyroidism are generally treatable. Prognosis depends on whether or not the patient has severe complications.

Sources

• http://www.endocrine.niddk.nih.gov/pubs/Hyperthyroidism/
• http://www.nlm.nih.gov/medlineplus/ency/article/000356.htm

Causes

Major causes in humans are:

• Graves' disease
• Toxic thyroid adenoma
• Toxic multinodular goitre

Other causes of hyperthyroxinemia (high blood levels of thyroid hormones) are not to be confused with true hyperthyroidism and include subacute and other forms of thyroiditis (inflammation) and struma ovarii (a teratoma). Thyrotoxicosis (symptoms caused by hyperthyroxinemia) can occur in both hyperthyroidism and thyroiditis. When it causes acutely increased metabolism, it is sometimes called "thyroid storm", a life-threatening event characterized by tachycardia, hypertension, and fever.

Excess thyroid hormone from pills can also cause hyperthyroidism. Amiodarone, a heart medication, can sometimes cause hyperthyroidism. Hamburger toxicosis is a condition that occurs sporadically and is associated with ground beef contaminated with thyroid hormone.

Postpartum thyroiditis occurs in about 7% of women during the year after they give birth. PPT typically has several phases, the first of which is hyperthyroidism. Many times, the hyperthyroidism corrects itself within weeks or months without any treatment necessary.

Life Threatening Causes

• Adenocarcinoma
• Choriocarcinoma
• Metastatic follicular thyroid cancer
• Pituitary tumor
• Struma ovarii
• Teratoma
• Testicular cancer
• Thyroid adenoma
• Thyroid carcinoma
• Thyroid nodule
• Thyroid tumor
• Thyrotropinoma
• Toxic adenoma
• Toxic thyroid adenoma
• Trophoblastic disease
• Tsh-producing pituitary adenoma

Common Causes

• Graves' disease
• Toxic thyroid adenoma
• Toxic multinodular goitre

Causes by Organ System

Cardiovascular	No underlying causes
Chemical/Poisoning	No underlying causes
Dental	No underlying causes
Dermatologic	Hydatidiform mole
Drug Side Effect	Amiodarone , Atezolizumab, Levothyroxine and indinavir interaction, Nivolumab, Potassium iodide, Pramipexole, Sorafenib, Thyroxine
Ear Nose Throat	No underlying causes
Endocrine	Anterior pituitary hyperhormonotrophic syndrome, Autoimmune enteropathy, Autoimmune thyroid disease, Autonomous thyroid tissue , Choriocarcinoma, De quervain thyroiditis, Excessive replacement therapy, Exogenous thyroid hormone intake, Factitious thyroiditis , Graves' disease , Hashimoto's thyroiditis, Jod-basedow thyrotoxicosis, Metastatic follicular thyroid cancer, Pituitary tumor, Polyendocrinopathy, Polyostotic fibrous dysplasia, Postpartum thyroiditis, Suppurative thyroiditis, Thyroid adenoma, Thyroid carcinoma, Thyroid nodule, Thyroid stimulating globulin, Thyroid tumor, Thyroiditis, Thyrotropinoma, Toxic adenoma, Toxic multinodular goiter, Toxic thyroid adenoma, Tsh hypersecretion, Tsh-mediated hyperthyroidism, Tsh-producing pituitary adenoma
Environmental	No underlying causes
Gastroenterologic	Enteropathy
Genetic	Glutaricaciduria type 3, Ipex syndrome , Mccune-albright syndrome , Troell-junet syndrome
Hematologic	Diabetes mellitus
Iatrogenic	Excessive replacement therapy, Exogenous thyroid hormone intake, Intentional suppressive therapy, Iodine overuse
Infectious Disease	Hashitoxicosis, Thyrotoxicosis factitia
Musculoskeletal/Orthopedic	No underlying causes
Neurologic	No underlying causes
Nutritional/Metabolic	Diabetes mellitus, Diarrhea
Obstetric/Gynecologic	Hyperemesis gravidarum, Teratoma, Trophoblastic disease
Oncologic	Adenocarcinoma, Choriocarcinoma, Metastatic follicular thyroid cancer, Pituitary tumor, Struma ovarii , Teratoma, Testicular cancer, Thyroid adenoma, Thyroid carcinoma, Thyroid nodule, Thyroid tumor, Thyrotropinoma, Toxic adenoma, Toxic thyroid adenoma, Trophoblastic disease, Tsh-producing pituitary adenoma
Ophthalmologic	No underlying causes
Overdose/Toxicity	Iodine overuse
Psychiatric	No underlying causes
Pulmonary	No underlying causes
Renal/Electrolyte	No underlying causes
Rheumatology/Immunology/Allergy	Autoimmune enteropathy, Autoimmune thyroid disease, Autonomous thyroid tissue , Immune dysregulation, Intentional suppressive therapy, Polyostotic fibrous dysplasia
Sexual	No underlying causes
Trauma	No underlying causes
Urologic	Testicular cancer
Miscellaneous	No underlying causes

Causes in Alphabetical Order

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Calssification

Classification

Hyperthyroidism can be classified according to the results of iodine uptake test into:

High iodine uptake

• Grave’s disease
• Toxic multinodular goiter
• Toxic thyroid adenoma

High or normal uptake:

• Iodine caused hyperthyroidism
• Hashitoxicosis
• Germ cell tumors (choriocarcinoma in males and testicular germ cell tumors)
• Pituitary TSH-producing adenoma

Low uptake

• Subacute thyroiditis
• Hyperthyroidism due to ectopic thyroid tissue