Dysfunctional Uterine Bleeding Causes

Ovulatory DUB (not associated with anovulation) is less common than anovulatory DUB, and the bleeding, though abnormally heavy, is usually regular.

Ovulatory DUB may be due to abnormalities in the 2-week luteal phase of menstruation that occurs just before bleeding begins. It can also result from an "atrophic endometrium" that can result from a high progesterone to estrogen ratio, which may occur in women who take progesterone-only contraceptives. A lack of cell-building estrogen causes the endometrium to slough off and bleed irregularly.

Patterns of Abnormal Uterine Bleeding

DUB can result in the following menstrual patterns:

  • polymenorrhea (frequent, regular periods that occur less than every 21 days)
  • hypermenorrhea (excessively heavy bleeding during a normal-length period)
  • menorrhagia (prolonged or excessive bleeding lasting longer than a week that occurs at regular intervals)
  • metrorrhagia (periods that occur at irregular intervals, or frequent bleeding of various amounts,though not heavy)
  • menometrorrhagia (frequent, excessive, and prolonged bleeding that occurs at irregular intervals)

Other Types of Abnormal Uterine Bleeding

Most abnormally heavy uterine bleeding has no underlying anatomical cause and is considered DUB. There are, however, underlying conditions that may cause similar symptoms. Diagnosing DUB involves ruling out other conditions, including the following:

  • uterine lesions (e.g., fibroids, polyps, cancer)
  • damage from an intrauterine contraceptive device (IUD)
  • pelvic inflammatory disease (bacterial infection of the uterus, fallopian tubes, and other areas of the pelvis)
  • adenomyosis (benign growth of the endometrium into the underlying muscular layer of the uterus)
  • ectopic pregancy (pregnancy that occurs outside of the uterus)
  • hydatid mole (abnormal mass in the uterus caused by a poorly developed or degenerating fertilized egg)
  • uterine leiomyoma (benign, fibrous tumor that occurs in up to 40% of women by age 40)
  • endometritis (inflammation of the endometrium caused by a bacterial infection)
  • trauma and sexual abuse
  • medications
  • foreign bodies (e.g., tampon, condom)

Publication Review By: Stanley J. Swierzewski, III, M.D.

Published: 31 Oct 2000

Last Modified: 14 Sep 2015