Causes of Missed Menstrual Cycles

While some women have menstrual cycles that are always regular, other women may experience skipped, infrequent or entirely absent menstrual periods at some point in their lives. If your menstrual cycle is missed for more than six months, the condition is called amenorrhea. According to the National Library of Medicine and the Mayo Clinic, the causes of missed menstrual cycles include lifestyle factors, certain medical conditions and medications.

Pregnancy and Breastfeeding

• During pregnancy, hormones in your body prevent your menstrual cycle from occurring, and if you are breastfeeding, you may not have a period for six months or longer after giving birth.

Body Weight

• If your body weight is too low or if you are obese, you may experience missed menstrual cycles and may be unable to get pregnant.

Stress

• Emotional stress may alter your hormone levels and delay your menstrual cycles for several weeks or even longer, until the cause of your stress is resolved.

Hormone Changes

• Hormone changes during puberty and menopause may cause skipped and irregular menstrual cycles that may result in much heavier bleeding than normal when you do have a period.

Gynecological Disorders

• Gynecological disorders such as polycystic ovarian syndrome (PCOS), premature ovarian failure, and damage or scarring of the uterus may cause missed menstrual cycles.

Medical Disorders

• Disorders of your pituitary or thyroid gland may cause an imbalance of the hormones that are needed to trigger your menstrual cycles.

• If you use synthetic steroids or hormonal birth control such as patches, pills, rings or IUDs, you may experience missed menstrual cycles, especially after starting these medications.