Night sweats are hot flashes that occur at night, associated with excess sweating that may soak nightclothes and bedsheets. Night sweats can be associated with both underactive or overactive thyroid function. However, there are numerous potential causes of night sweats, such as menopause, low blood sugar, certain drugs, or other medical conditions. Tell your doctors if you are experiencing night sweats and they can evaluate for possible causes.
For more information go the endocrinediseases.org:
Diseases of thyroid function: Hyperthyroidism