Menstruation, or a menstrual period, refers to the monthly process in which the uterus sheds blood and tissue in preparation for pregnancy.

Not having or missing a menstrual period is called amenorrhea. This condition is divided into two types:

  • Primary amenorrhea—when an adolescent female has not yet begun menstruation by around age 16 years
    • Most females begin menstruating between the ages 9-18, but age 12 is the average.
  • Secondary amenorrhea—when a woman who has previously menstruated misses three or more periods in a row

Menstrual Flow

Menstrual Flow

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Causes

The most common cause of secondary amenorrhea is pregnancy. If nonpregnant women, may be due to a variety of factors.

Risk Factors

Factors that may increase the risk of amenorrhea include:

  • Dramatic weight loss (eg, from extreme diets, eating disorders, or excessive exercise) or dramatic weight gain
  • Malnourishment
  • Birth defects (eg, lack of female reproductive organs)
  • Chromosomal or hormonal abnormalities
  • Certain conditions (eg, thryoid disorder, pituitary tumor)
  • Medicines (eg, certain contraceptives)
  • Emotional distress
  • Uterine scarring
Symptoms

The main symptom for primary amenorrhea is the absence of a menstrual period in a female by age 16 or older. The main symptom for secondary amenorrhea is three or more missed periods in a row in a woman who has previously had menstrual periods.

When Should I Call My Doctor?

Call your doctor if you:

  • Have not had your first period and are aged 16 years or older
  • Miss having your period
Diagnosis

Your doctor will ask about your symptoms and medical history. A physical exam will also be done.

Tests may include:

  • Pregnancy test
  • Progestin challenge test to determine if a lack of estrogen is causing amenorrhea
  • Blood work to check hormone levels
  • Chromosome test to determine if there are any abnormalities

Other tests that may be ordered include:

Treatment

Treatment will depend on what is causing amennorhea. Examples include:

  • Weight-related cause—A healthy caloric intake and exercise routine usually restores hormonal balance and menstruation.
  • Birth defect—Surgery may be needed.
  • Hormonal irregularity—Your doctor may prescribe hormonal therapy.
  • Emotional distress—Relaxation techniques (eg, deep breathing), therapy, and exercise may help to decrease stress.
  • Pituitary tumor—Surgery, radiation therapy, or medicine may be needed.
Prevention

Amenorrhea may or may not be preventable, depending on the cause. Follow these general guidelines to prevent amenorrhea:

  • Maintain an appropriate level of body fat.
  • Get help for an eating disorder.
  • Treat conditions that can lead to amenorrhea, such as polycystic ovary syndrome, pituitary tumor, and hypothyroidism.