A normal period lasts between 2 and 7 days. If yours is stretching past that seven-day mark, something is causing your uterine lining to shed more slowly or more heavily than it should. The causes range from hormonal shifts and new birth control to growths in the uterus, and most are treatable once identified.
Hormonal Imbalances
Your period length depends on a careful balance between two hormones: estrogen and progesterone. Estrogen builds up the uterine lining each cycle, and progesterone signals the lining to stop growing and shed in an orderly way. When progesterone is too low relative to estrogen, the lining grows thicker than normal and takes longer to break down, which extends bleeding.
Polycystic ovary syndrome (PCOS) is one of the most common reasons for this imbalance. Women with PCOS often skip ovulation, which means their bodies produce little to no progesterone for stretches of time. The lining keeps thickening under estrogen’s influence, and when it finally sheds, the result is prolonged or unusually heavy bleeding.
Thyroid problems create a different kind of disruption. An overactive thyroid raises progesterone and shifts other reproductive hormones in ways that can make periods irregular, closer together, or longer. An underactive thyroid can also cause heavier, drawn-out bleeding. Both are diagnosed with a simple blood test.
Uterine Fibroids and Polyps
Fibroids are noncancerous growths in the muscular wall of the uterus. They change the shape or surface area of the uterine lining, giving it more tissue to shed and making it harder for the uterus to contract and stop bleeding efficiently. Fibroids are extremely common, especially in women over 30, and can range from tiny to grapefruit-sized.
Polyps are different. They form when cells in the uterine lining overgrow and create small projections that attach to the uterine wall by a base or thin stalk. They can be as small as a sesame seed or as large as a golf ball. Polyps cause irregular bleeding, very heavy flow, and bleeding between periods. Both fibroids and polyps are typically found with an ultrasound and can be removed if they’re causing problems.
Your Birth Control Method
The copper IUD is well known for making periods heavier and longer, particularly in the first few months after insertion. This happens because the copper triggers a low-level inflammatory response in the uterus that increases blood flow. For most women, this side effect eases after three to six months. If you’re still dealing with extended bleeding beyond that window, it’s worth discussing alternatives.
Hormonal birth control can also cause prolonged bleeding, though in a different pattern. Starting or switching pills, patches, or implants sometimes triggers breakthrough bleeding or spotting that blurs into what feels like a period that never ends. This usually resolves within the first two to three cycles as your body adjusts.
Bleeding Disorders and Other Causes
Some women bleed longer simply because their blood doesn’t clot as efficiently. Von Willebrand disease, the most common inherited bleeding disorder, affects up to 1 in 100 people and often goes undiagnosed until a woman notices that her periods have always been unusually heavy or long. If you’ve also had frequent nosebleeds, easy bruising, or prolonged bleeding after dental work, a clotting disorder is worth investigating.
Other possible causes include early pregnancy complications (including miscarriage or ectopic pregnancy, which can mimic a prolonged period), infections of the uterus or cervix, and, less commonly, precancerous changes in the uterine lining. This is why persistent changes in your bleeding pattern shouldn’t be ignored, even if the bleeding itself doesn’t feel alarming.
How the Cause Is Found
Figuring out why your period is lasting longer than usual typically starts with a detailed conversation about your cycle history, followed by a pelvic exam. From there, blood work checks for thyroid issues, anemia, clotting disorders, and pregnancy. If a structural problem like fibroids or polyps is suspected, a pelvic ultrasound can usually confirm it. Women over 45, or younger women with risk factors like PCOS or obesity, may also have a small tissue sample taken from the uterine lining to rule out abnormal cell growth.
How Prolonged Periods Are Treated
Treatment depends entirely on the cause, but for heavy or prolonged bleeding without a clear structural issue, a hormonal IUD is considered the most effective first-line option. In clinical comparisons, it reduced menstrual blood loss by about 82 mL per cycle more than anti-inflammatory medications alone.
If hormonal options aren’t right for you, a medication that helps blood clot more effectively at the uterine lining can significantly reduce bleeding. Anti-inflammatory pain relievers like ibuprofen also reduce menstrual flow, though modestly, cutting blood loss by about 36 mL per cycle compared to a placebo. They work best as a complement to other treatments rather than a standalone solution.
For fibroids or polyps causing the problem, removal through a minimally invasive procedure often resolves the bleeding entirely. Your doctor may use a small camera inserted through the cervix to locate and remove the growth without any external incisions.
The Anemia Connection
Losing more blood each month than your body can easily replace puts you at risk for iron deficiency anemia. If your periods have been long or heavy for a while and you’ve noticed increasing fatigue, shortness of breath during normal activities, or feeling lightheaded, your iron stores may be depleted. A blood test measuring your ferritin (stored iron) and hemoglobin levels will show whether anemia has developed. Rebuilding iron through diet or supplements takes time, so catching it early matters.
Supplements That May Help
Some nutrients have modest evidence for reducing menstrual blood flow. Vitamin E (200 IU daily, started two days before your period and continued for three days into it) has been shown to reduce both pain and flow. Fish oil supplements at 1 gram daily may help with cramping and pain, though at higher doses they can thin the blood, which could work against you if heavy bleeding is already the issue.
These aren’t substitutes for medical treatment if something structural or hormonal is driving your prolonged periods, but they can be a reasonable addition to your overall approach.
Signs You Need Urgent Care
Most prolonged periods are more disruptive than dangerous, but certain patterns signal a need for immediate attention. Soaking through two or more pads or tampons per hour for two to three consecutive hours is a red flag. So is feeling dizzy, faint, or noticeably short of breath, which can indicate you’ve lost enough blood to affect your circulation. If bleeding is that intense, it’s an emergency room situation rather than a wait-for-an-appointment situation.