Hyperthyroidism

Pronunciation

Definition 1

Too much thyroid hormone. Symptoms include weight loss, chest pain, cramps, diarrhea, and nervousness. Also called overactive thyroid. (NCI Dictionary)

Definition 2

Overactivity of the thyroid gland resulting in overproduction of thyroid hormone and increased metabolic rate. Causes include diffuse hyperplasia of the thyroid gland (Graves' disease), single nodule in the thyroid gland, and thyroiditis. The symptoms are related to the increased metabolic rate and include weight loss, fatigue, heat intolerance, excessive sweating, diarrhea, tachycardia, insomnia, muscle weakness, and tremor. (NCI Thesaurus)

Definition 3

A disorder characterized by excessive levels of thyroid hormone in the body. Common causes include an overactive thyroid gland or thyroid hormone overdose. (NCI Thesaurus/CTCAE)

More information

Your thyroid is a butterfly-shaped gland in your neck, just above your collarbone. It is one of your endocrine glands, which make hormones. Thyroid hormones control the rate of many activities in your body. These include how fast you burn calories and how fast your heart beats. All of these activities are your body's metabolism. If your thyroid is too active, it makes more thyroid hormones than your body needs. This is called hyperthyroidism.

Hyperthyroidism is more common in women, people with other thyroid problems, and those over 60 years old. Grave's disease, an autoimmune disorder, is the most common cause. Other causes include thyroid nodules, thyroiditis, consuming too much iodine, and taking too much synthetic thyroid hormone.

The symptoms can vary from person to person. They may include

• Being nervous or irritable
• Mood swings
• Fatigue or muscle weakness
• Heat intolerance
• Trouble sleeping
• Hand tremors
• Rapid and irregular heartbeat
• Frequent bowel movements or diarrhea
• Weight loss
• Goiter, which is an enlarged thyroid that may cause the neck to look swollen

To diagnose hyperthyroidism, your doctor will look at your symptoms, blood tests, and sometimes a thyroid scan. Treatment is with medicines, radioiodine therapy, or thyroid surgery. No single treatment works for everyone. (NIH: National Institute of Diabetes and Digestive and Kidney Diseases)