7. Menstrual Abnormalities
Both underactive and overactive thyroids can disrupt women’s menstrual cycles, and like other condition-dependent symptoms, the nature of the changes depend on whether the patient is suffering from hypothyroidism or hyperthyroidism. Women with underactive thyroids may experience lighter than normal periods, and they may also miss periods altogether.
On the other hand, overactive thyroids can cause heavier than normal periods, or periods which last several days longer than normal. The menstrual cycle itself may shorten, and spotting can occur.