A woman with heavy menstrual periods bleeds more than usual, or longer than usual during a menstrual period. Increased bleeding occurs commonly as women approach menopause.

Criteria for heavy menstrual periods include:

• Menstrual bleeding that lasts more than 7 days
• The total amount of bleeding during the menstrual period exceeds one third of a cup (80 ml)

About 10 to 20 percent of women experience vaginal bleeding that meets the criteria for excessive bleeding.