Symptoms of an overactive thyroid gland include frequent bowel movements, weight loss, irregular periods, insomnia, and nervousness. Hypothyroidism can sometimes prevent ovulation, but a bigger problem is that once a woman with an overactive thyroid is pregnant, her metabolism may be so out of balance that the pregnancy can’t go to term. After you’re diagnosed with hyperthyroidism, medical treatments (including antithyroid drugs or radioactive iodine) will put the brakes on to restore normal function.
