Irregular Periods

Overview of Irregular Periods

Menstrual bleeding is considered irregular if it occurs more frequently than every 21 days, lasts longer than 7 days or is heavy. Irregular bleeding also includes infrequent periods, including menstrual intervals greater than 35 days, skipped months or absent periods.

Irregular periods are a common condition in women and can be caused by many things. Your health care provider will want to be sure the source of the problem is not related to a complication of a pregnancy, a problem with the uterus, ovary or a hormonal disorder. Most of the time the irregular periods are related to a condition called “anovulation.” This is a medical term for an imbalance between the hormones of the pituitary gland, the ovaries and the hypothalamus. Anovulation means that for that cycle an “egg” is not released from the ovary while the ovary continues to produce estrogen and fails to produce progesterone. The influence of these hormone imbalances creates a fragile, thickened uterine lining that may shed in an abnormal pattern.

Signs & Symptoms

  • A cycle length (from day 1 of your last menses to day 1 of the next menses) of less than 21 days or greater than 35 days.
  • A missed period.
  • Bleeding between periods.
  • A period that lasts longer than 7 days.
  • A heavy period (changing tampons or pads every hour for > 4 hours).


There is no real prevention for many of these conditions. It is helpful to keep a menstrual calendar to record your menstrual cycle and pattern of bleeding for approximately 3 months in a row. This may help your health care provider determine the kind of work up necessary to determine the cause of the irregular bleeding.


Once your health care provider has determined the cause of your irregular bleeding, the treatment will be based on the cause. If it is determined that your irregular bleeding is caused by anovulatory cycles, hormones in the form of birth control pills, patch or ring may be suggested to regulate and manage your cycles.

How We Can Help

  • If you would like to be seen by our medical staff, please contact our Appointment Desk to schedule an appointment.
  • Also, our Advice Nurse service is available at no charge for all UC Davis students to discuss health concerns and the need for medical care.