The medical term used to describe “absence of periods” is amenorrhea. Women normally do not menstruate before puberty, during pregnancy, and after menopause. If a woman does not get her period when she normally should, it may be the symptom of a treatable medical condition.

There are two types of amenorrhea: primary amenorrhea and secondary amenorrhea. Primary amenorrhea is when a young woman has not had her first period by the age of 16. Secondary amenorrhea is when a woman who has had normal menstrual cycles stops getting her monthly period for 3 or more months.
What Causes Amenorrhea?

Amenorrhea can be caused by any number of changes in the organs, glands, and hormones involved in menstruation.

Possible causes of primary amenorrhea (when a woman never gets her first period) include:

• Failure of the ovaries (female sex organs that hold eggs).

• Problems in the central nervous system (brain and spinal cord) or the pituitary gland (a gland in the brain that makes hormones involved in menstruation).

• Poorly formed reproductive organs.

In many cases, the cause of primary amenorrhea is not known.

Common causes of secondary amenorrhea (when a woman who has had normal periods stops getting them) include:

• Pregnancy
• Breast feeding
• Stopping the use of birth control
• Menopause
• Some birth control methods, such as Depo-Provera
• Certain drugs

Other causes of secondary amenorrhea include:

• Stress
• Poor nutrition
• Depression
• Extreme weight loss
• Over-exercising
• Ongoing illness
• Sudden weight gain or being very overweight (obesity)
• Hormonal imbalance due to polycystic ovarian syndrome (PCOS)
• Thyroid gland disorders
• Tumors on the ovaries or brain (rare)

A woman who has had her uterus or ovaries removed will also stop menstruating.