Menstruation: Missed Periods

What is a missed period?

Normally women start having periods when they reach puberty. Then, unless they are pregnant or breast-feeding, they keep having a menstrual period every month until they reach menopause, usually in their 50s. You have missed a period if you go 2 or more months without having a period.

The absence of menstrual periods or menstrual flow is called amenorrhea. Amenorrhea may be either primary or secondary.

• Primary amenorrhea is not starting to have menstrual periods by the age of 15.
• Secondary amenorrhea is not having periods some time after you started having periods.

How do they occur?

A lot of things can cause you to miss 1 or more periods. There could be problems with your uterus, cervix (opening to the uterus), vagina, or ovaries. The pituitary gland and the hypothalamus, both located in the brain, also must be working properly. A problem with any of these parts of the body may keep you from having a period.

Primary amenorrhea

The main cause of primary amenorrhea is late puberty. It is fairly common in girls who are very thin or very athletic. You need a certain amount of body fat to trigger the hormones that start the menstrual cycle.

Other possible causes are:

• hormone problems, such as problems with the thyroid gland
• genetic problems
• birth defects (like a vagina that does not have an opening that allows menstrual blood to escape)

Secondary amenorrhea

The most common reasons for no longer having periods after you started having them are:

• pregnancy
• menopause
• breast-feeding
• use of hormonal birth control, like the progesterone IUD or Depo-Provera shot.

Some other possible causes are:

• stress
• thyroid problems, such as an underactive or overactive thyroid gland
• a problem with the ovaries
• very low body weight
• vigorous exercise, such as long-distance running
• increased production of the hormone prolactin by the pituitary gland
• drugs, such as tranquilizers and antidepressants
• rapid weight gain or loss
• a pituitary tumor
• some medicines
• scarring of the uterus after some procedures

Periods also stop after a hysterectomy (surgical removal of the uterus).

How is it diagnosed?

When you don't have your periods, most of the time it does not mean you have a serious disease. But it's not always easy to figure out why the periods have stopped. Your provider will ask about your medical history. You will have a thorough physical exam, including a pelvic exam. You may have a pregnancy test, blood tests, X-rays, ultrasound scans, CT scans, or chromosome studies.

How is it treated?

The treatment depends on the cause. Examples of possible treatments are:

• exercising less if you have a very strenuous exercise program
• learning to manage stress if stress may be a cause
• birth control pills or other hormone medicine to help you get back the right balance of hormones
• surgery

In some cases, depending on the results of tests and your plans to have children, you may not need treatment.

How long will the effects last?

You may not have a period for 6 to 8 weeks or longer after you stop taking birth control pills or other types of hormonal birth control.

If stress or an illness has interrupted the hormone cycle, your periods should start again naturally. However, how long you will go without periods cannot be predicted.

Untreated amenorrhea can result in weakened bones (osteoporosis). You may have trouble getting pregnant or other health problems.

How can I take care of myself?

• If you miss more than 2 periods in a row, see your provider.
• Follow your provider's recommendations closely.
• If your periods are irregular, keep a record of the dates that they start, how long they last, the amount of menstrual flow, and any symptoms.
• If you have no periods at all, try to remember when you had your last period, how long it lasted, and the amount of menstrual flow. Share this information with your healthcare provider.
• Tell your provider about any medicine you are taking, both prescription and nonprescription.
• Try to find out if others in your family have had a problem like yours.

How can I help avoid missed periods?

You can help keep your periods normal with a healthy lifestyle:

• Make changes in your diet or activities so you can have a healthy weight.
• Avoid excessive use of alcohol and mood-altering stimulants or sedative drugs.
• Don't smoke.
• Get the help you need to lower stress and problems in your life. Talk to your friends, family, or a counselor for support.
• Try to balance your work, activities, and rest.