What should I do about light menstrual flow and breast tenderness?

If you’re experiencing both reduced menstrual flow (hypomenorrhea) and breast tenderness (mastalgia), it’s important to consider that these symptoms often reflect underlying hormonal fluctuations—particularly involving estrogen, progesterone, and prolactin. Common causes include anovulatory cycles, luteal phase deficiency, elevated prolactin levels (hyperprolactinemia), thyroid dysfunction (especially subclinical or overt hypothyroidism), polycystic ovary syndrome (PCOS), perimenopause, or stress-related hypothalamic-pituitary-ovarian axis suppression. Certain medications—including selective serotonin reuptake inhibitors (SSRIs), antipsychotics, and hormonal contraceptives—can also contribute.

A thorough clinical evaluation is essential. This should include a detailed menstrual history (cycle regularity, duration, associated symptoms), reproductive history, medication review, and physical examination—with particular attention to breast exam (to rule out focal pathology) and signs of hyperandrogenism or thyroid disease. First-line investigations typically include serum tests for thyroid-stimulating hormone (TSH), prolactin, follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol, and possibly testosterone and dehydroepiandrosterone sulfate (DHEA-S). Pelvic ultrasound may be indicated if PCOS or structural abnormalities are suspected.

Management depends on the identified cause. For example, levothyroxine is indicated for hypothyroidism; dopamine agonists (e.g., cabergoline) for hyperprolactinemia; lifestyle modification and insulin sensitizers (e.g., metformin) for PCOS-related anovulation; and cyclical progestin or combined hormonal therapy may be considered for luteal insufficiency or perimenopausal transition—always individualized based on age, fertility goals, and contraindications. Non-pharmacologic strategies—such as stress reduction, regular moderate exercise, and maintaining a healthy body weight—can support endocrine balance. If symptoms persist, worsen, or are accompanied by red flags (e.g., galactorrhea, amenorrhea, unilateral breast mass, or postmenopausal bleeding), prompt referral to a gynecologist or endocrinologist is warranted.