The normal menstrual cycle lasts about 28 days and it can be shorter or longer by about 7 days. Each cycle starts with the first day of bleeding of one period and ends with the first day of the next.
When menstrual cycles are longer than 35 days or shorter than 21 days, it becomes abnormal. When menstruation does not occur for 3 to 6 months, this is called amenorrhea, and should be of concern.
Abnormal uterine bleeding (AUB) is irregular bleeding from the uterus that is longer or heavier than usual or does not occur at your regular time. Bleeding in any of the following situation is abnormal:
- Bleeding between periods
- Bleeding after sex
- Spotting anytime in the menstrual cycle
- Bleeding heavier or for more days than usual
- Bleeding after menopause
AUB occurs in any age, but there is a certain time of a woman’s life that their menses are irregular. For example, menses in a girl, a few years after her first menses (menarche), may not occur on schedule. Also, cycle length may change when women is nearing menopause.
Abnormal uterine bleeding has many causes. It is sometimes caused by changes in hormone levels. It can also be caused by problems such as growths in the uterus or clotting problems.
In some cases the cause of the bleeding isn’t known, then it is known as a dysfunctional uterine bleeding (DUB). This reflects a disruption in the hormones.