Reasons for a Late Menstrual Cycle

While most women do not welcome the arrival of their period each month, it can be cause for concern when their menstrual cycle is late or fails to arrive at all. Most of the reasons for a late menstrual cycle are easy to identify and regulate, although some of the reasons for a late menstrual cycle may require medical attention and intervention. Having one late or missing menstrual cycle is fairly common for most women, but if the menstruation fails to return for months at a time, a woman should schedule an appointment with her gynecologist to determine the cause.

Pregnancy and Breast-feeding

• The most common reason for a late menstrual cycle is pregnancy, and for many women who have been trying to conceive, the absence of a period is both expected and welcome. Pregnancy is a possible reason for a late menstrual cycle for all sexually active women, whether they have been using contraception or not, so taking a pregnancy test when a menstrual cycle is late should always be the first step to discovering the reason for the missed period.
  Breast-feeding is also a primary reason for a late menstrual cycle. Women who breast-feed their infants exclusively often do not have their menstrual cycle for several months after the birth of their child, with the menstrual cycle sometimes not returning until the baby is entirely weaned.

Weight Loss or Gain

• Another common reason for a late menstrual cycle is rapid weight loss or gain. Quick or excessive weight gain or loss can disrupt many of the body's usual functions, including the menstrual cycle, as the body adjusts itself to such rapid changes. Excessive exercise can also cause a late menstrual cycle, especially in those with very low body fat like professional athletes. Eating disorders, including anorexia and bulimia, are also reasons for a late menstrual cycle.

Age

• It is common for young women in their first few years of menstruation to have irregular and late menstrual cycles. It can take quite awhile for the body to regulate the hormones involved in the menstrual cycle, but once these hormones are balanced, a teenager's menstrual cycle should become more regular.
  Women approaching menopause also often experience late or missing menstrual cycles as their bodies prepare for the total cessation of menstruation.

Stress

• Most women at some point in their lives will experience this quite common reason for a late menstrual cycle: stress. Emotional and physical stress can take a great toll on the body and its various functions, like the normal governance of the menstrual cycle.
  Associated with stress as reasons for a late menstrual cycle are fatigue and illness. Both are stressors for the body that can disrupt the normal timing of the menstrual cycle. Recovery, rest and stress management are the best ways to restore the normal functioning of the menstrual cycle.

Birth Control Methods

• Using birth control, most notably birth control pills, is also one of the frequent reasons for a late menstrual cycle. Women currently taking birth control pills may experience light and even missing periods due to a very low level of estrogen in the medication, while women coming off the pill may have a late menstrual cycle as their body adjusts to controlling the menstrual cycle on its own.

Hormonal Imbalance

• Hormonal imbalances, infections, sexually transmitted diseases (STDs) and problems with the pelvic organs are other reasons for a late menstrual cycle that are considered more serious and require medical attention. Hormonal imbalances can often be regulated through hormone therapy to return the menstrual cycle, while infections and STDs may need to be treated with prescription drugs. Common problems with the pelvic organs that might delay a menstrual cycle include polycystic ovary syndrome, Asherman's syndrome and a imperforate hymen. A gynecologist can diagnose these conditions and advise proper treatment.