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Dysfunctional uterine bleeding (DUB)

  • Definition

    Dysfunctional uterine bleeding (DUB) is abnormal bleeding from the vagina that is due to changes in hormone levels.


    Alternative Names

    Anovulatory bleeding; Bleeding - dysfunctional uterine; DUB; Abnormal uterine bleeding; Menorrhagia - dysfunctional; Polymenorrhea - dysfunctional; Metrorrhagia - dysfunctional


    Causes, incidence, and risk factors

    The menstrual cycle, or period, is not the same for every woman. On average, menstrual flow occurs every 28 days (most women have cycles between 24 and 34 days apart), and lasts 4 - 7 days.

    The menstrual cycle of young girls who are just starting to have their periods can range from 21 to 45 days or more apart. Women in their 40s will often notice their menstrual cycles occurring less often.

    During a normal menstrual cycle, levels of different female hormones made by your body go up and down. Estrogen and progesterone are two very important hormones.

    Ovulation is the part of the normal menstrual cycle when an egg is released from the ovaries. The most common cause of dysfunctional uterine bleeding is when your ovaries do not release an egg. When this occurs, the hormone levels in your body are not the same, causing your period to be later or earlier and heavier than normal.

    Other changes in hormones may also cause changes in your period.

    See also: Menstrual periods - heavy, prolonged or irregular for information on other causes of vaginal bleeding.