Overview Of Irregular Menstrual Periods
For most women, a normal menstrual cycle ranges from 21 to 35 days. However, 14% to 25% of women have irregular menstrual cycles, meaning the cycles are shorter or longer than normal; are heavier or lighter than normal; or are experienced with other problems, like abdominal cramps. Irregular menstrual periods can be ovulatory, meaning that ovulation occurs, or anovulatory, meaning ovulation does not occur.
The most common irregular menstrual periods include:
- Amenorrhea or absent menstrual periods: When a woman does not get her period by age 16, or when she stops getting her period for at least 3 months and is not pregnant.
- Oligomenorrhea or infrequent menstrual periods: Periods that occur more than 35 days apart.
- Menorrhagia or heavy menstrual periods: Also called excessive bleeding. Although anovulatory bleeding and menorrhagia are sometimes grouped together, they do not have the same cause and require different diagnostic testing.
- Prolonged menstrual bleeding: Bleeding that exceeds 8 days in duration on a regular basis.
- Dysmenorrhea: Painful periods that may include severe menstrual cramps.
Additional irregular menstrual periods include:
- Polymenorrhea: Frequent menstrual periods occurring less than 21 days apart
- Irregular menstrual periods with a cycle-to-cycle variation of more than 20 days
- Shortened menstrual bleeding of less than 2 days in duration
- Intermenstrual bleeding: Episodes of bleeding that occur between periods, also known as spotting
Abnormal menstrual periods may have a variety of causes, such as endometrial hyperplasia, endometrial polyps, uterine fibroids, and abnormal thyroid or pituitary function. The endometrium is the tissue lining the uterus. When the endometrium becomes unusually thick it is called endometrial hyperplasia. Hyperplasia may cause profuse or extended menstrual bleeding.