Spotting (aka metrorrhagia, from "metro" meaning "womb", "rrhagia" meaning "excessive flow", aka intermenstrual bleeding, IMB) is vaginal bleeding at irregular intervals, particularly between expected menstrual periods.

• Normal and harmless part of ovulation, in some women
• Women using hormonal contraceptives (e.g. IUD's, OCP's), known as breakthrough bleeding (aka breakthrough spotting), have mid-cycle bleeding. If spotting continues beyond the first 3 cycles of OCP use, a woman should have her prescription changed to a pill containing either more estrogen or more progesterone. Withdrawal bleeding occurs when a hormonal contraceptive is discontinued
• Underlying disorder, including:
  • Hormone imbalance
  • Endometriosis
  • Uterine fibroids
  • Cancer of the reproductive organs

• Significant iron deficiency anemia → due to repeated and heavy bleeding

• Mittelschmerz (pain that occur at the same time as menstrual spotting)
• Hypomenorrhea (very light menstruation)
• Oligomenorrhea (infrequent menstruation)
• Menorrhagia (excessive quantity of menstrual bleed)