Complex interactions among hormones control the start of menstruation during puberty, the rhythms and duration of menstrual cycles during the reproductive years, and the end of menstruation at menopause (which is usually defined as beginning 12 months after a woman's last period).
The hormonal interactions that control menstruation occur in the following sequence:
-
The hypothalamus (a part of the brain that coordinates and controls hormonal activity) releases gonadotropin-releasing hormone in pulses.
-
Gonadotropin-releasing hormone stimulates the pituitary gland to produce two hormones called gonadotropins: luteinizing hormone and follicle-stimulating hormone.
-
Luteinizing hormone and follicle-stimulating hormone stimulate the ovaries.
-
The ovaries produce the female hormones estrogen and progesterone, which ultimately control menstruation.
Hormones produced by other glands, such as the adrenal glands and the thyroid gland, can affect the functioning of the ovaries and menstruation.
Changes During the Menstrual Cycle
Deciphering Medical Terms for Menstrual Disorders*
Term |
Description |
|
No periods |
|
|
Dysmenorrhea |
Menstrual cramps or painful periods |
|
Hypomenorrhea |
Unusually light periods |
|
Menometrorrhagia |
Heavy bleeding during menstrual periods and bleeding that occurs frequently and irregularly between periods |
|
Menorrhagia (hypermenorrhea) |
Unusually long and/or heavy periods |
|
Metrorrhagia |
Bleeding that occurs frequently and irregularly between periods |
|
Oligomenorrhea |
Unusually infrequent periods |
|
Polymenorrhea |
Unusually frequent periods |
|
Postmenopausal bleeding |
Bleeding that occurs after menopause |
|
Severe psychologic symptoms that occur before the start of a period, end when or shortly after the period starts, and interfere with daily activities and/or relationships |
|
|
Premenstrual syndrome (PMS) |
Physical and psychologic symptoms that occur before the start of a period |
|
Primary amenorrhea |
No periods ever starting (at puberty) |
|
Secondary amenorrhea |
Periods that started and have stopped |
|
* Breaking the words into their components helps decipher them: a = no; dys = painful (or abnormal); hypo = deficient (or below normal); men = month; metro = uterus; oligo = few or scanty; poly = many or much; post = after; pre = before; rhagia = to burst forth; rhea = flow. |
|
During the reproductive years, vaginal bleeding may be abnormal when menstrual periods are too heavy or too light, last too long, occur too often, or are irregular. Any vaginal bleeding that occurs before puberty or after menopause is considered abnormal until proven otherwise. Most causes of abnormal vaginal bleeding are not serious.
Menstrual disorders include
-
Absence of menstrual periods (amenorrhea)
-
Menstrual cramps (dysmenorrhea)
-
Premature menopause (primary ovarian insufficiency)
-
Premenstrual syndrome (PMS)
Some disorders that are related to the reproductive organs but not specifically to the menstrual cycle cause some of the same symptoms as menstrual disorders. These disorders include
