Sandbox: hyperthyroidism
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# 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 depends 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 depends 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
- PhentermineIf 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.

# Possible Complications

# Sources

# Overview
Hyperthyroidism is the clinical syndrome caused by an excess of circulating free thyroxine (T4) or free triiodothyronine (T3), or both.

# Historical Perspective

# Classification

# Pathophysiology

# Causes

# Differentiating Hyperthyroidism from other Diseases

# Epidemiology and Demographics

# Risk Factors

# Screening

# Natural History, Complications and Prognosis

# Diagnosis

## History and Symptoms

## Physical Examination
Minor ocular signs, which may be present in any type of hyperthyroidism, are eyelid retraction ("stare") and lid-lag. These "fear-like" eye-signs result from thyroid hormone's exacerbation of the action of norepinephrine. In hyperthyroid stare (Dalrymple sign) the eyelids are retracted upward more than normal (the normal position is at the superior corneoscleral limbus, where the "white" of the eye begins at the upper border of the iris). In lid-lag (von Graefe's sign), when the patient tracks an object downward with their eyes, the eyelid fails to follow the downward moving iris, and the same type of upper globe exposure which is seen with lid retraction occurs, temporarily. These signs disappear with treatment of the hyperthyroidism, or treatment by certain anti-adrenergic drugs.

## Laboratory Findings
A diagnosis is suspected through blood tests, by measuring the level of thyroid-stimulating hormone (TSH) in the blood. A low TSH (the job of TSH taken over by thyroid-stimulating immunoglobulin  that act like TSH) indicates increased levels of T4 and/or T3 in the blood. Measuring specific antibodies, such as anti-TSH-receptor antibodies in Graves' disease, may contribute to the diagnosis.

## Electrocardiogram

## Chest X Ray

## CT

## MRI

## Echocardiography or Ultrasound

## Other Imaging Findings
In all patients with hyperthyroxinemia, scintigraphy is required in order to distinguish true hyperthyroidism from thyroiditis.

## Other Diagnostic Studies

# Treatment

## Medical Therapy
The major and generally accepted modalities for treatment of hyperthyroidism in humans involve initial temporary use of suppressive thyrostatics medication, and possibly later use of permanent surgical or radioisotope therapy. All approaches may cause under active thyroid function (hypothyroidism) which is easily managed with levothyroxine supplementation.

## Surgery
Surgery as an option predates the use of the less invasive radioisotope therapy, but is still required in cases where the thyroid gland is enlarged and causing compression to the neck structures, or the underlying cause of the hyperthyroidism may be cancerous in origin.

## Primary Prevention

## Secondary Prevention

## Cost-Effectiveness of Therapy

## Future or Investigational Therapies

# Case Studies

## Case #1