Cleveland Clinic explains that the average period lasts from four to seven days. Chronically long periods lasting longer than seven days may be an underlying symptom of another condition. Stress and birth control methods are linked to abnormal menstruation. WebMD states that copper intrauterine devices, or IUDs, are linked to painful, prolonged periods that may persist throughout the use of the birth control method.
Moreover, Cleveland Clinic explains that longer periods could be a sign of uterine fibroids, endometriosis, pelvic inflammatory disease, polycystic ovary syndrome or premature ovary failure. Uterine fibroids are tumors that cause heavy, prolonged periods related to the increased blood supply within the uterus. Endometriosis causes intensely painful cramping during periods in addition to prolonged bleeding. Pelvic inflammatory disease causes long periods, a foul smell, heavy discharge, fever, nausea and chills. Other conditions linked to abnormal periods are uterine cancer, cervical cancer, steroids, anticoagulants, anemia, hypothyroidism, hyperthyroidism, pituitary disorders, hormonal imbalances and pregnancy complications.
To determine if the prolonged period is something serious, keep a menstruation diary, recommends Cleveland Clinic. Write down all symptoms and take the diary to the doctor. A Pap smear, blood tests, physical examination, family history and hysterosalpingography can be used to determine the underlying cause of a prolonged period.