Menstrual Health: Cycles, Disorders & Treatment: Topical Map, Topic Clusters & Content Plan

A normal cycle ranges about 21–35 days for adults, with bleeding typically lasting 3–7 days; variation of up to 7–9 days between cycles can be normal. See a clinician if cycles are consistently shorter than 21 days or longer than 35 days, if you miss three consecutive periods (secondary amenorrhea), or if irregularity is new and accompanied by weight change, hair growth, or infertility.

Most periods last 3–7 days; bleeding is considered heavy (menorrhagia) if you lose more than ~80 mL per cycle, soak through a pad/tampon every 1–2 hours, or pass large clots. If you need to change protection frequently, have iron-deficiency symptoms (fatigue, breathlessness), or have heavy bleeding that affects daily life, get medical evaluation including CBC and ferritin.

Common causes include anovulation from PCOS, thyroid disorders, hyperprolactinemia, significant weight loss/gain or exercise, stress, and perimenopause; pregnancy must always be excluded first. Basic workup in primary care includes pregnancy testing, TSH, prolactin, and consideration of pelvic ultrasound or referral if structural causes or persistent abnormalities are suspected.

First-line, evidence-based treatments include tranexamic acid during menses, regular NSAIDs, combined hormonal contraceptives, and the levonorgestrel intrauterine device (LNG-IUD); choice depends on whether pregnancy is desired. If bleeding persists despite medical therapy, investigate with pelvic ultrasound and consider gynecologic referral for endometrial sampling or surgical options like endometrial ablation or hysterectomy depending on cause and childbearing plans.

PCOS commonly causes oligo- or amenorrhea due to chronic anovulation and is associated with hyperandrogenism and polycystic ovarian morphology; it increases risks of infertility, metabolic syndrome, and endometrial hyperplasia if cycles are infrequent. Management focuses on lifestyle and weight optimization, menstrual regulation with combined hormonal contraception or LNG-IUD, metabolic screening, and ovulation induction (letrozole first-line) when pregnancy is desired.

For primary dysmenorrhea use regular NSAIDs started at symptom onset or before menses, combined hormonal contraception or a progestin-only method for longer-term control, plus heat and exercise. If pain is progressively worsening, not responsive to first-line measures, associated with infertility, or has focal pelvic findings, investigate for secondary causes like endometriosis or adenomyosis with pelvic imaging and specialist referral.

Ovulation typically occurs about 12–16 days before the next period, so the fertile window is roughly five days before ovulation through the day of ovulation. People with irregular cycles should use LH ovulation kits, cervical mucus tracking, or consult fertility services after 12 months of trying (6 months if age ≥35) because timing is less predictable.

Initial steps include a pregnancy test, review of medications, weight and exercise history, and blood tests for TSH and prolactin; consider FSH and estradiol if menopausal transition is suspected. If initial testing is inconclusive, proceed to pelvic ultrasound and targeted endocrine testing or refer to gynecology/endocrinology for suspected ovarian insufficiency, PCOS, or hypothalamic amenorrhea.

Medical management includes combined hormonal contraceptives, continuous progestins, levonorgestrel IUDs, and GnRH agonists/antagonists for moderate-to-severe disease; add-back therapy reduces hypoestrogenic side effects for GnRH analogues. When pain is severe, refractory to medication, or fertility is a priority, laparoscopic excision of lesions by an experienced surgeon is recommended alongside multidisciplinary pain and fertility support.