Abnormal uterine bleeding

What it is

Abnormal uterine bleeding is bleeding abnormal in frequency, regularity, volume or duration. Normal frequency is every 21-34 days; cycles are irregular if the cycle to cycle variation is more than 20 days over 12 months; normal volume is 5-80 ml and normal duration 4.5-8 days. The older names follow from those four: metrorrhagia is intermenstrual bleeding, oligomenorrhea a cycle length over 34 days, polymenorrhagia a cycle length under 21 days, menorrhagia a heavy period (>80 ml) or one prolonged beyond 8 days, and hypo-menorrhagia a light period (<5 ml). Chronic AUB is bleeding of 6 months or more. Ovulatory AUB is associated with ovulation and occurs at regular cycles; anovulatory AUB occurs irregularly. Abnormal uterine bleeding is a symptom, not a diagnosis, and its prevalence is 10% to 30% among women of reproductive age. Any bleeding is abnormal before menarche and after menopause, and any vaginal bleeding in a postmenopausal woman must be investigated. The sources do not agree on the normal cycle itself: one gives a frequency of 21-34 days and a duration of 4.5-8 days, the other a frequency of 24 to 38 days lasts 7 to 9 days; both put blood loss at 5 to 80 milliliters.