The menstrual cycle is not the same for every woman. On average, menstrual flow occurs every 28 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 two 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. Irregular periods happen more often than every 21 days or less often than every 35 days.

These variations may be normal and are less concerning than bleeding, pain, or discharge between periods.

Bleeding may be something to worry about 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 in your urine, you think it 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) and cancers
• 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

Keep a record of your menstrual cycles, including when menstruation begins and ends, how much flow you have (count numbers of pads and tampons used, noting whether they are soaked), and any other symptoms you experience. Tampons should be changed at least twice a day to avoid infection.

Bed rest may be recommended if bleeding is heavy.

Because aspirin may prolong bleeding, it should be avoided. Ibuprofen is usually more effective than aspirin for relieving menstrual cramps.

PREVENTION

• Follow a healthy diet, avoiding fat.
• If you are trying to lose weight, do so gradually.
• Change exercise routine slowly. Work your way up over time to more strenuous activities.
• Practice relaxation techniques.

Call your doctor if:

• You have soaked through a pad or tampon every hour for 6 hours.
• Your bleeding has lasted longer than one week.
• You are pregnant.
• You have severe pain, especially if you also have pain when not menstruating.
• Your periods have been heavy or prolonged for 3 or more cycles, compared to what is normal for you.
• You have a fever or abnormal vaginal discharge, especially if it has an odor.
• You have bleeding after menopause.
• You have bleeding or spotting between periods.
• You have nipple discharge, excessive hair growth, deepening voice, unintentional weight loss or gain, or new acne.