A menstrual cycle is a finely tuned process, and when it deviates from its typical rhythm, concern is understandable. A “normal” menstrual period generally lasts between two and seven days, repeating roughly every 21 to 35 days. When bleeding extends past this seven-day limit or becomes unusually heavy, it is considered abnormal uterine bleeding (AUB) and warrants medical investigation. This prolonged or excessive bleeding can disrupt daily life and may indicate an underlying health issue.
Defining Abnormal Menstrual Bleeding
Abnormal uterine bleeding (AUB) is the medical term for any bleeding pattern that falls outside established norms for frequency, duration, or volume. Heavy menstrual bleeding (HMB) is defined as blood loss exceeding 80 milliliters per cycle or lasting longer than seven days. Since measuring blood loss accurately at home is difficult, simple benchmarks are used to determine if bleeding is excessive.
Signs of excessive bleeding include soaking through one or more pads or tampons every hour for several consecutive hours, or the consistent passage of blood clots larger than a quarter. Bleeding that occurs at irregular times, such as spotting between periods, is called intermenstrual bleeding. Prolonged and heavy bleeding places a person at risk for developing iron deficiency anemia due to chronic blood loss.
Underlying Causes of Prolonged Bleeding
The reasons for prolonged or heavy bleeding are organized into categories that include both structural issues within the uterus and non-structural factors like hormonal imbalances. Structural causes involve physical changes that can increase the bleeding surface area or interfere with the muscle’s ability to contract and stop the flow. These include uterine fibroids, which are non-cancerous muscular tumors that grow in the wall of the uterus and are a common cause of heavy bleeding.
Polyps, which are small growths of endometrial tissue on the inner lining of the uterus, can also cause prolonged or irregular bleeding. Adenomyosis is a condition where the tissue that normally lines the uterus grows into the muscular wall of the uterus itself, often leading to a larger, softer uterus and heavier, more painful periods. Malignancy or pre-cancerous changes in the uterine lining must also be ruled out, especially in older reproductive-aged individuals.
Non-structural causes often relate to the hormonal regulation of the cycle, particularly the balance between estrogen and progesterone. Ovulatory dysfunction, where an egg is not released consistently, results in the uterine lining continuing to build up without the proper hormonal signal to shed predictably. This imbalance is common in conditions like Polycystic Ovary Syndrome (PCOS), thyroid disorders, and during the transition to menopause, known as perimenopause.
Certain medications can also contribute to prolonged bleeding, specifically blood thinners used to treat or prevent clotting disorders. The use of certain contraceptives, particularly the copper intrauterine device (IUD), can increase menstrual blood loss and duration. Inherited bleeding disorders, such as von Willebrand disease, can impair the blood’s ability to clot effectively, resulting in excessive menstrual flow. Even an early, unrecognized pregnancy complication, such as a miscarriage or ectopic pregnancy, can sometimes present as unexpectedly heavy or prolonged bleeding.
Immediate Warning Signs Requiring Urgent Care
While prolonged or heavy bleeding is common, certain symptoms signal an acute medical situation requiring immediate attention. Urgent care is needed when the rate of blood loss is so rapid that it overwhelms the body’s ability to compensate. This is defined by soaking through two or more standard pads or tampons every hour for two to three hours consecutively.
Severe blood loss can quickly lead to hypovolemia (a low blood volume state), which manifests as lightheadedness, dizziness, or fainting. Other signs of instability include a rapid heart rate, severe shortness of breath, or paleness in the skin and gums. Passing blood clots the size of a golf ball or larger indicates dangerously heavy and uncontrolled bleeding. If these acute symptoms occur, immediate medical evaluation is necessary.
Diagnosis and Management Options
Addressing prolonged bleeding involves a thorough patient history and physical examination, including a pelvic exam. Initial laboratory work typically includes a complete blood count to check for anemia and iron deficiency, a pregnancy test, and tests of thyroid function and specific hormone levels. These tests help identify underlying systemic issues like a bleeding disorder or hormonal imbalance.
Imaging is often performed using a transvaginal ultrasound, which provides detailed views of the uterus and ovaries to detect structural problems like fibroids or adenomyosis. For a clearer view of the uterine lining, a specialized procedure called saline infusion sonohysterography may be utilized. Treatment is always tailored to the specific diagnosis and the patient’s goals, such as the desire for future pregnancy.
Management often begins with non-hormonal medications, such as nonsteroidal anti-inflammatory drugs (NSAIDs) taken during the period to reduce blood volume by up to 35 percent. Tranexamic acid is another non-hormonal option that helps stabilize blood clots and significantly reduces bleeding. Hormonal therapies, including combination birth control pills or a levonorgestrel-releasing intrauterine system (LNG-IUD), are effective at thinning the uterine lining and controlling bleeding.
When medications fail or a structural issue is the cause, surgical options may be discussed. For polyps or specific types of fibroids, a minimally invasive procedure called hysteroscopy can remove the growth. Other procedures, such as endometrial ablation, use heat or cold to destroy the uterine lining, which dramatically reduces flow but eliminates the possibility of future pregnancy. If all other treatments have been unsuccessful, a hysterectomy remains the definitive method to stop all uterine bleeding.