Periods vary widely from woman to woman. Some periods are punctual, some are unpredictable. On average, a woman gets her period every 21 to 35 days. A period usually lasts about three to five days. Treatment of irregular periods depends on the cause and your desire to have children in the future. Irregular periods can be caused by many different things. Changes in your body s level of the hormones estrogen and progesterone can disrupt the normal pattern of your period. That s why young girls going through puberty and women approaching menopause commonly have irregular periods.Treatments for irregular periods due to other causes may include: Correcting or treating underlying disease Changing your type of birth control Lifestyle changes, including weight loss Hormone therapy Surgery Hormone therapy (HT). An irregular menstrual cycle is often due to a lack or imbalance of certain hormones in the body. Birth control pills (oral contraceptives) often containing the hormones estrogen and progesterone are commonly prescribed to help control irregular periods. A hormone medication called progestin can also help trigger periods in women who do not get them.