Menstrual Cycle Characteristics in Women With and Without Thyroid Disease

This study was designed to evaluate the frequency and type of menstrual disorders in thyroid dysfunction. The relationship between thyroid dysfunction and menstrual disorders has been known for a long time. The menstrual cycle should be checked in women with thyroid dysfunction. On the contrary, women with menstrual irregularities should be investigated for thyroid dysfunction.

Women who presented to our hospital's internal medicine and endocrinology clinics that recently diagnosed thyroid dysfunction were included. The patients were divided into five groups (subclinical hypothyroidism, overt hypothyroidism, subclinical hyperthyroidism, overt hyperthyroidism, and euthyroid) according to thyroid functions. They were questioned regarding the amount, frequency, and duration of menstrual bleeding. The prevalence of menstrual disturbances, including secondary amenorrhea, hypomenorrhea, oligomenorrhea, hypermenorrhea, polymenorrhea, menorrhagia, metrorrhagia, and menometrorrhagia, was examined in 485 patients and 108 healthy controls.

Hypermenorrhea was significantly more common in patients with overt hypothyroidism (33%) than in controls (6%) (p<0.05). The types and frequencies of menstrual disorders in patients with hyperthyroidism and those with normal thyroid function were not significantly different from those in controls.

Menstrual abnormalities frequently occur in women with thyroid dysfunction. Therefore, menstrual dysfunction should be considered when treating patients with thyroid abnormalities.