Irregular menstruation; Heavy, prolonged, or irregular periods; Menorrhagia; Polymenorrhea; Metrorrhagia and other menstrual conditions

The menstrual cycle is not the same for every woman. On average, menstrual flow occurs every 28 days (with most women having cycles between 24 and 34 days), and lasts about 4 days. However, there is wide variation in timing and duration that is still considered normal, especially if your periods began within the last few years.

If you soak through a sanitary pad or tampon every hour for 6 consecutive hours, this is considered a very heavy period. A prolonged period is one that lasts longer than 7 days.

A small percentage of women have periods more often than every 21 days or less often than every 35 days. These variations may be normal.

Bleeding may be something to worry about if it occurs between periods, after intercourse, or if you are over age 50, especially if you have already gone through menopause. The risk of cancer increases with age.

Often, if you are bleeding from the rectum or there is blood in your urine, you may think the blood is coming from the vagina. To know for certain, insert a tampon into the vagina to confirm that it's the source of your bleeding.

• Anovulation (failure of ovaries to produce, mature, or release eggs)
• Endometrial polyps (the endometrium is the inner lining of the uterus)
• Endometrial hyperplasia (thickening/build up of the uterine wall)
• Endometrial cancer
• Uterine fibroids
• Abnormal thyroid or pituitary function
• Pregnancy complications -- like miscarriage or ectopic pregnancy (when a fertilized egg implants somewhere other than the uterus)
• Hormonal changes, such as menopause
• Changes in birth control pills or estrogens that you take
• Use of certain drugs like steroids or blood thinners (for example, warfarin or Coumadin)
• Use of an intrauterine device (IUD) for birth control
• Recent trauma, surgery, or other uterine procedure
• Pelvic inflammatory disease or other infection
• Stress, change in diet or exercise routine, recent weight loss or weight gain, travel, or illness

Osei J, Critchley H. Menorrhagia, mechanisms and targeted therapies. Curr Opin Obstet Gynecol. 2005; 17(4): 411-418.

James AH. More than menorrhagia: a review of the obstetric and gynaecological manifestations of bleeding disorders. Haemophilia. 2005; 11(4): 295-307.

Warner PE, Critchley HO, Lumsden MA, Campbell-Brown M, Douglas A, Murray GD. Menorrhagia I: measured blood loss, clinical features, and outcome in women with heavy periods: a survey with follow-up data. Am J Obstet Gynecol. 2005; 192(6): 2093-2095.