Symptoms of hyperthyroidism arise from the elevated levels of thyroid hormones produced by the overactive thyroid gland. Excessive intake of thyroid hormones can produce these symptoms as well. Characteristic symptoms include a rapid heart rate, excessive sweating, intolerance to heat, tremor, nervousness, or agitation. Other symptoms can include fatigue, weight loss, hair loss, increased appetite, problems with concentration, frequent bowel movements, and irregular or decreased menstrual blood flow in women. Sometimes, thyroid nodules or an enlarged thyroid gland (goiter) are apparent. With severe hyperthyroidism, cardiac arrhythmias, fever, high blood pressure, and heart failure can develop.
Causes of hyperthyroidism
There are many causes of hyperthyroidism. Graves' disease is a generalized overactivity of the thyroid gland and the most common cause of hyperthyroidism. Other causes include thyroid growths or tumors that produce thyroid hormone such as functioning adenoma and toxic multinodular goiter (TMNG). Excessive intake of thyroid hormones or excessive iodine intake can cause the condition. Other causes can include abnormal secretion of TSH and thyroiditis (inflammation of the thyroid gland).
Other hyperthyroidism symptoms and signs
- Agitation
- Arrhythmias (Abnormal Heartbeat)
- Clammy Skin
- Difficulty Concentrating
- Fatigue
- Fever
- Frequent Bowel Movements
- Goiter
- Hair Loss
- Heart Failure
- Heat Intolerance
- High Blood Pressure
- Hyperactivity
- Increased Appetite
- Increased Sweating
- Irregular Menstrual Periods
- Itching
- Nausea
- Nervousness
- Palpitations
- Sleep Disturbances
- Swelling Around the Eyes (Apparent Protrusion of the Eyes)
- Thyroid Nodule
- Tremor
- Vomiting
- Warm Skin
- Weakness
- Weight Loss
Main Article on Hyperthyroidism Symptoms and Signs

SLIDESHOW
Hyperthyroidism: Symptoms, Treatment, Medication See SlideshowPictures, Images, Illustrations & Quizzes
-
Hyperthyroidism: Symptoms, Treatment, Medication
What are the symptoms of hyperthyroidism? What causes hyperthyroidism? What happens when you take thyroid medication?...
-
Picture of Graves Disease
Graves’ disease. Graves’ disease is an autoimmune disease in which your thyroid works harder than it needs to (hyperthyroidism)....
-
Thyroid Quiz: Test Your Medical IQ
Your unexplained change in weight could indicate a thyroid condition. Take the Thyroid Quiz to learn about common symptoms and...
-
Your Thyroid: Common Thyroid Problems and Diseases Explained
Learn about thyroid problems such as hyperthyroidism, hypothyroidism, thyroid cancer, and more. Discover symptoms and treatments...
Examples of Medications for Hyperthyroidism Symptoms and Signs
From 
Healthy Resources
Featured Centers
Health Solutions From Our Sponsors
Subscribe to MedicineNet's General Health Newsletter
By clicking Submit, I agree to the MedicineNet's Terms & Conditions & Privacy Policy and understand that I may opt out of MedicineNet's subscriptions at any time.