Absence of Menstruation (Amenorrhea)

Most women have between 11 and 13 menstrual periods each year. You may be different. You may have more or fewer. Missed or irregular periods must be looked at in terms of what is normal for you.

Menstrual periods often aren't regular during the first few years after your period starts. It may take several years for the hormones that control menstruation to reach a balance.

Periods also may be very irregular at the other end of the menstrual years. Many women realize that they are approaching perimenopause and menopause when their periods stop being regular. Menopause occurs when it has been 12 months since you had a period.

Pregnancy is the most common cause of a missed period. If you might be pregnant, treat yourself as if you are pregnant until you know for sure. Use a home pregnancy test as the first step to find out if you are pregnant.

If you aren't pregnant, other causes of missed or irregular periods include:

  • Excessive weight loss or gain. Low body weight is a common cause of missed or irregular periods. Obesity also can cause menstrual problems.
  • Eating disorders, such as anorexia or bulimia.
  • Increased exercise. Missed periods are common in endurance athletes.
  • Emotional stress.
  • Illness.
  • Travel.
  • Medicines such as birth control methods. These may cause lighter, less frequent, more frequent, or skipped periods or no periods at all.
  • Hormone problems. They may cause a change in the levels of the hormones that the body needs to support menstruation.
  • Illegal drug use.
  • Problems with the pelvic organs, such as an imperforate hymen, polycystic ovary syndrome, or Asherman's syndrome.
  • Breastfeeding. Many women don't resume regular periods until they have finished breastfeeding.

Remember, you can still become pregnant even though you don't have periods. Practice birth control if you don't wish to become pregnant.

Premature ovarian failure is when you stop having periods before age 40. It can be caused by surgery, chemotherapy, and radiation therapy to the belly or pelvis.

Other diseases such as irritable bowel syndrome, tuberculosis, liver disease, and diabetes can cause missed or irregular periods. But this is rare. If you have any of these diseases, you will usually have other symptoms besides periods that aren't regular.

If you've skipped a period, try to relax. Restoring your life to emotional and physical balance can help. Many women miss periods now and then. Unless you're pregnant, your cycle likely will return to normal next month.