There are many factors which contribute to irregular menstrual periods in some women. These include the following:

• Drug abusers can also have some irregularities in their periods.
• Some eating disorders like bulimia nervosa and anorexia nervosa also cause menstrual cycle irregularities.
• Increased stress  may cause of irregular menstruation in some cases.
• A disease called Polycystic Ovarian Syndrome can cause estrogen dominance in the blood which can be the cause of irregularities in the menstrual cycle.   
•  Uterine abnormalities such as polyps, cysts, fibroids and endometriosis.
• Recent child birth or miscarriage may cause irregularity.
• Some women have period irregularities when they breast feeding.
• There can be some changes in menstrual cycle at the beginning of menopause in a woman.

The above reasons can cause irregularities in the menstrual cycle. If you are concerned about irregular menstrual periods in yourself or a family member or a friend, then it is recommended to discuss these issues with your health care professional.

Jitesh Arora. To know lot more about Menstruation Cycle, visit http://www.talkhealthonline.com where you will find every thing you need to know about Women's health .