Possible Causes of HyperthyroidismA number of different conditions can cause hyperthyroidism. Some of the causes of an overactive thyroid include:
- Graves' disease (the most common cause)
- Thyroid nodules
- Thyroiditis (inflammation of the thyroid gland)
- Consuming too much iodine (iodine-induced hyperthyroidism)
- Taking too much synthetic thyroid hormone (a common treatment for hypothyroidism)
- A pituitary adenoma.
Graves' disease affects about 2 percent of all women at some point in their lives. It tends to affect women between the ages of 20 and 40. The disease can also affect males, infants, children, and the elderly.
(Click Hyperthyroidism Causes for more information about these conditions.)
Signs and Symptoms of HyperthyroidismThere are many symptoms or combinations of symptoms that a person with an overactive thyroid may develop. Sometimes, a person may not even have symptoms -- these cases are diagnosed based on blood tests. This is known as subclinical hyperthyroidism.
A few of the possible symptoms of hyperthyroidism include:
- Increased sweating
- Low tolerance for heat
- Weight loss, even though the person is not trying to lose weight
- A goiter, which is an enlarged thyroid that may cause the neck to look swollen.
Age can affect the symptoms a person experiences. For example, older adults may lose their appetites, whereas younger people tend to have increased appetites. Older adults may also seem disinterested or withdraw socially. This is why hyperthyroidism can be misdiagnosed as depression or dementia in older adults.
(Click Hyperthyroidism Symptoms and Signs for a longer list of possible symptoms seen with this condition.)