Absence of Menstrual Periods - Amenorrhea

Overview, Causes, & Risk Factors

A woman who has amenorrhea has either never had a menstrual period or has stopped having periods.

What is going on in the body?

There are two categories of amenorrhea:

  • Primary amenorrhea is not having had a period by age 16.
  • Secondary amenorrhea is the absence of periods in a woman who previously had regular menstrual cycles.

    • To have a period, a woman must have a normal, healthy:

  • uterus, cervix or opening to the uterus, vagina, and ovaries
  • pituitary gland
  • hypothalamus, a structure within the skull that controls much of the body's hormone production

    • An abnormality in any of these may keep a woman from having a period.

    What are the causes and risks of the condition?

    Primary amenorrhea is usually due to late puberty rather than any permanent problem. The reason for this delay is generally not known, though it may be a family trait. Other possible causes are:

  • a genetic disorder, such as Turner's syndrome
  • a hormonal problem, such as an improperly functioning thyroid gland

    • Pregnancy is the most common reason for secondary amenorrhea. A woman's periods may also stop temporarily due to:

  • breastfeeding
  • birth control pills
  • the birth control shot, such as medroxyprogesterone acetate
  • levonorgestrel implants

    • A woman's periods may not start up again for a while after she stops using birth control pills, shots or implants. Usually, periods will start again within 3 to 6 months.

    Secondary amenorrhea may also be linked to:

  • depression
  • emotional stress
  • poor nutrition
  • drugs, such as tranquilizers or antidepressants
  • rapid weight loss or gain
  • chronic systemic illnesses, such as kidney failure or cancer
  • too much exercise
  • recent surgery
  • a hormonal imbalance, such as polycystic ovary syndrome (PCOS)