Secondary amenorrhea occurs when a woman who has been having normal menstrual cycles stops getting her periods for 6 or more months.

Amenorrhea is when a woman does not get her monthly menstrual cycle, or period.

See also:

• Menstruation - Absent
• Primary amenorrhea

Amenorrhea - secondary; No periods - secondary; Absent periods - secondary; Absent menses - secondary; Absence of periods - secondary

Women who are pregnant, breastfeeding, or in menopause are not considered to have secondary amenorrhea.

Women who are taking birth control pills or receive hormone shots such as Depo-Provera may not have any monthly bleeding. When they stop taking these hormones, their periods may not return for more than 6 months.

You are more likely to have amenorrhea if you:

• Are obese
• Exercise excessively and for long periods of time
• Have less than 15% - 17% body fat
• Have severe anxiety or emotional distress
• Lose a lot of weight suddenly (for example, with a strict diet or after gastric bypass surgery)

Other causes include:

• Brain (pituitary) tumors
• Polycystic ovarian syndrome
• Premature ovarian failure
• Thyroid dysfunction

The following drugs may also cause missed periods:

• Busulfan
• Chemotherapy drugs for cancer
• Chlorambucil
• Cyclophosphamide
• Phenothiazines

Also, procedures such as a dilation and curettage (D and C) can lead to scar tissue formation that may cause a woman to stop menstruating. This is called Asherman syndrome. Scarring may also be caused by some severe pelvic infections.

• No menstrual period for 6 months or longer
• Previously had one or more menstrual periods that started on their own

Other symptoms that can occur with secondary amenorrhea include:

• Breast size changes
• Considerable weight gain or weight loss
• Discharge from the breast (galactorrhea)
• Headache
• Increased hair growth in a "male" pattern (hirsutism) and acne
• Vaginal dryness
• Voice changes

If amenorrhea is caused by a pituitary tumor, there may be other symptoms related to the tumor, such as vision loss.

A physical exam and pelvic exam must be done to rule out pregnancy. A pregnancy test will be done.

Blood tests may be done to check hormone levels, including:

• Estradiol levels
• Follicle stimulating hormone (FSH level)
• Luteinizing hormone (LH level)
• Prolactin level
• Serum hormone levels such as testosterone levels
• Thyroid stimulating hormone (TSH)

Other tests that may be performed include:

• CT scan of the head
• Endometrial biopsy
• Genetic testing
• MRI of the head
• Ultrasound of the pelvis or hysterosonogram

Treatment depends on the cause of the amenorrhea. Normal monthly periods usually return after the condition is treated.

For example, if the primary disorder is hypothyroidism, amenorrhea will be cured when it is treated with thyroid supplements.

If the primary cause is obesity, vigorous exercise, or weight loss, treatment may include a change in exercise routine or weight control.

The outlook depends on the cause of amenorrhea. Most of the conditions that cause secondary amenorrhea will respond to treatment.

Complications depend on the cause of the condition. Amenorrhea may be harmless, or it may be associated with overgrowth of the uterine lining (endometrial hyperplasia). This can sometimes lead to uterine cancer.

There may be other complications, depending on the cause of the amenorrhea.

Call for an appointment with your primary health care provider or OB/GYN provider if you have missed more than one period so that you can get diagnosed and treated, if necessary.

Prevention depends on the cause. For example, moderate exercise instead of extreme exercise, weight control, and other measures may be helpful.

Lobo RA. Abnormal uterine bleeding: Ovulatory and anovulatory dysfunctional uterine bleeding, management of acute and chronic excessive bleeding. In: Katz VL, Lentz GM, Lobo RA, Gershenson DM, eds. Comprehensive Gynecology. 5th ed. Philadelphia, PA: Mosby Elsevier; 2007:chap 37.

Master-Hunter T, Heiman DL. Amenorrhea: evaluation and treatment. Am Fam Physician. 2006;73(8):1374-1382.