Thyroid Disorders in Women

Thyroid disorders can cause abnormally early or late onset of puberty and menstruation. In addition, abnormally high or low levels of thyroid hormone can cause very light or very heavy menstrual periods, very irregular menstrual periods, or absent menstrual periods (a condition called amenorrhea).

An overactive or underactive thyroid may also affect ovulation (the release of an egg for fertilization). Thyroid disorders may prevent ovulation from occurring at all. In addition, the ovaries are at an increased risk for cyst development if the woman has an underactive thyroid (hypothyroid). Severe hypothyroidism can actually cause milk production in the breast, while preventing ovulation.

Thyroid disorders during pregnancy can harm the fetus and may lead to postpartum thyroid problems, such as postpartum thyroiditis.

Thyroid disorders may cause the early onset of menopause (before age 40 or in the early 40s). In addition, some symptoms of hyperthyroidism (overactive thyroid), such as lack of menstruation, hot flashes, insomnia, and mood swings may be mistaken for early menopause. Treating hyperthyroidism sometimes can alleviate symptoms of, or the actual onset of, early menopause.