Prolonged menstruation is defined as a menstrual period that lasts longer than seven days, and can also be referred to as menorrhagia. As the menstrual period is the shedding of the uterine lining, one of the most common causes of excessive bleeding is a particularly thick lining. Uterine fibroids and cysts can also result in longer than normal menstruation. In some cases, though, prolonged menstruation is caused by the inability of the blood to clot properly, which may be due to either anticoagulant medications or blood disorders.
An abnormally thick uterine lining may occur for various reasons, with one of them being the approach of menopause. This is because ovulation is often delayed in older women, resulting in many cycles that do not involve the release of an egg. This means that no progesterone is produced, so the uterine lining continues to grow due to the high amount of estrogen still present. When progesterone is finally released during a cycle, the lining begins to shed, but it may take a few more days than usual to eliminate all the extra tissue and blood. While periods may be particularly long just before menopause, the same can occur just after the first menstrual period in girls, as the uterine lining may be thicker than normal.
Uterine fibroids can also result in prolonged menstruation, though the exact reason for this effect is unknown. One detail that is known about fibroids is that they seem to thrive on the presence of estrogen, which is why they typically only show up in women who menstruate regularly. Aside from prolonged menstruation, symptoms of fibroids include pelvic cramping, painful intercourse, and increased urinary frequency. On the other hand, ovarian cysts can also result in prolonged menstruation, and can usually be described as fluid-filled sacs that show up on the ovary. Other symptoms of cysts can include bloating and dull pelvic pain.
Most women do not experience prolonged menstruation because their body knows when to stop the blood flow by clotting it, which tends to happen within three to seven days after the period starts. In some women, however, normal coagulation does not occur, often due to clotting disorders like von Willebrand disease. In addition, women using anticoagulants, such as warfarin, may notice prolonged menstruation since the medication makes it difficult for the body to clot the blood as needed. In such cases, seeking treatment for the clotting disorder, or stopping use of the anticoagulant, should result in shorter menstrual periods.