11 Thyroid Problem Early Warning Signs You Should Not Ignore

8. Menstrual changes and fertility issues

Thyroid hormones interact with reproductive hormones, so menstrual cycles and fertility can shift when the thyroid is out of balance. Low thyroid function commonly causes heavier, more frequent periods and can interfere with ovulation, making conception harder. It can also raise prolactin in some cases, which affects menstrual regularity. Overactive thyroid may reduce period regularity or cause lighter cycles. For people trying to conceive, untreated thyroid disease raises the risk of miscarriage, preterm birth, and developmental issues, so timely screening is important. If your periods change without another clear reason, or if you face difficulty conceiving, include thyroid testing in your evaluation. Fertility clinics and obstetricians often work with endocrinologists to manage these cases safely during pregnancy.