A normal period lasts four to five days, with most falling within a three-to-seven-day range. If your bleeding has pushed past seven days, or it’s heavier than usual with no sign of tapering off, something is disrupting the normal process that tells your uterus to stop shedding its lining. The causes range from harmless hormonal shifts to conditions that need treatment, and figuring out which one applies to you depends on a few key details.
What Makes a Period Stop Normally
Each month, your body builds up the lining of the uterus in preparation for a potential pregnancy. If no pregnancy occurs, levels of the hormone progesterone drop sharply, triggering the lining to shed in an organized way. That shedding is your period. Once the old lining is gone, clotting factors and tissue repair kick in, and the bleeding stops within a few days.
When this process breaks down, the lining either doesn’t shed cleanly, keeps growing unevenly, or repairs too slowly. The result is bleeding that drags on well beyond a week, sometimes fluctuating between light spotting and heavier flow rather than following the usual heavy-to-light pattern.
The Most Common Reason: You Didn’t Ovulate
The single most frequent explanation for a period that won’t quit is a cycle where ovulation never happened. Without ovulation, your body doesn’t produce the surge of progesterone needed to stabilize the uterine lining. Instead, estrogen continues stimulating the lining to grow in a patchy, disorganized way. Because the lining was never properly organized, it can’t shed cleanly. Sections break down at different times, leading to prolonged, unpredictable bleeding that may be light one day and heavy the next.
Missed ovulation (called anovulation) is extremely common and doesn’t necessarily signal a serious problem. It happens more often during certain life stages: the first few years after your period starts, the years leading up to menopause, and during times of significant stress, rapid weight change, or intense exercise. Polycystic ovary syndrome (PCOS) is another well-known cause. If you’ve been under unusual stress lately, changed your eating or exercise habits significantly, or are in your early teens or mid-40s, a skipped ovulation is the most likely culprit behind your prolonged bleeding.
New Birth Control Can Cause Weeks of Bleeding
If you recently started a new hormonal contraceptive, that’s a strong candidate. Spotting and irregular bleeding are among the most common side effects when your body adjusts to hormonal birth control, and for some people, that adjustment period involves bleeding that seems to never end.
With hormonal IUDs, irregular bleeding and spotting in the first few months after placement is normal and typically settles down within two to six months. The implant works differently: the bleeding pattern you experience in the first three months tends to be the pattern you’ll have going forward. So if you’ve had an implant for three months and the bleeding hasn’t improved, it’s worth discussing alternatives with your provider rather than waiting it out. Pills, patches, and rings can also cause breakthrough bleeding, especially if doses are missed or the timing is inconsistent.
Growths and Structural Changes in the Uterus
Fibroids (noncancerous growths in the uterine wall) and polyps (small growths on the uterine lining) are physical reasons your period might drag on. They increase the surface area of the lining, disrupt normal blood vessel patterns, and interfere with the uterus’s ability to contract and clamp down on bleeding vessels. Fibroids are particularly common in people over 30 and can cause periods that are both longer and heavier than usual.
Adenomyosis, a condition where the uterine lining grows into the muscular wall of the uterus, causes similar symptoms. The uterus becomes enlarged and boggy, and periods tend to be painful, prolonged, and heavy. These structural issues don’t resolve on their own and generally require imaging to identify.
Thyroid Problems and Bleeding Disorders
Your thyroid gland influences your menstrual cycle more than you might expect. Both an underactive and overactive thyroid can disrupt the hormonal signals that regulate ovulation and lining buildup, leading to periods that are abnormally long or heavy. If your prolonged bleeding comes with other symptoms like unusual fatigue, weight changes, feeling cold all the time, or hair thinning, a thyroid issue is worth investigating.
Bleeding disorders also deserve mention because they’re underdiagnosed. Von Willebrand disease, the most common inherited bleeding disorder, affects the blood’s ability to clot efficiently. People with this condition often have heavy, prolonged periods starting from their very first cycle but assume it’s normal because they have no point of comparison. If your periods have always been long and heavy, and you bruise easily or bleed a lot from minor cuts, a clotting disorder could be the underlying issue.
How Heavy Is Too Heavy
Duration matters, but so does volume. A typical period produces about two to three tablespoons of blood total. Heavy menstrual bleeding involves roughly double that amount. The practical markers to pay attention to: needing to change your pad or tampon more often than every three hours, passing blood clots larger than a quarter, or soaking through a pad or tampon every hour for several consecutive hours. That last one, soaking through protection every hour, signals you should seek medical attention promptly rather than waiting for a scheduled appointment.
Prolonged or heavy bleeding is one of the leading causes of iron deficiency anemia worldwide. If your period has been going on for an extended stretch and you’re feeling dizzy, short of breath during normal activities, unusually exhausted, or noticing your heart racing when it shouldn’t be, you may already be anemic. These symptoms mean your body is running low on the red blood cells it needs to carry oxygen.
What Happens at the Doctor’s Office
Figuring out why your period won’t stop usually starts with a physical exam, bloodwork, and a conversation about your cycle history. A complete blood count checks for anemia and infection. You’ll likely be tested for pregnancy (even if you don’t think it’s possible, because abnormal bleeding can be an early sign of complications like ectopic pregnancy or miscarriage). Thyroid function and clotting disorders may also be checked through blood tests.
Depending on your age and symptoms, imaging comes next. An ultrasound can reveal fibroids, polyps, ovarian cysts, or a thickened uterine lining. If more detail is needed, a hysteroscopy uses a thin, lighted scope inserted through the cervix to look directly at the inside of the uterus. An endometrial biopsy, where a small sample of the uterine lining is taken and examined under a microscope, may be recommended, particularly for people over 35 or those with risk factors for uterine abnormalities.
How Prolonged Bleeding Is Treated
Treatment depends entirely on the cause, which is why getting evaluated matters more than trying to manage it at home indefinitely.
For hormonal imbalances and anovulatory cycles, hormonal treatments are the most common approach. A short course of progesterone can stabilize the lining and trigger an organized shed, essentially resetting the cycle. Ongoing management might involve hormonal birth control to regulate cycles and prevent the lining from building up unevenly.
For bleeding that needs to be slowed down quickly regardless of the cause, a non-hormonal medication that helps blood clot more effectively can be prescribed. It’s taken as a tablet for up to five days during each period and works by helping the body’s natural clotting process hold rather than break down prematurely.
Fibroids and polyps may need to be removed if they’re causing persistent symptoms. Thyroid disorders are treated with medication that brings hormone levels back to normal, which typically resolves the menstrual irregularity as a downstream effect. Bleeding disorders are managed with targeted treatments that address the specific clotting problem.
What to Track Before Your Appointment
If you’re planning to see a provider, the information that helps most is concrete. Write down how many days you’ve been bleeding, how many pads or tampons you’re going through per day, whether you’re passing clots (and roughly how large), and whether the flow is steady or comes in waves. Note any other symptoms: fatigue, dizziness, pain, or changes in your cycle pattern over the past several months. If you’re on any hormonal medication or recently changed or stopped one, mention that first, because it immediately narrows the list of likely causes.