A period that lasts longer than usual typically signals a shift in your hormones, though several other causes can explain it too. Normal periods last between 2 and 7 days. If your bleeding consistently stretches past 7 days, or if a period that used to wrap up in 4 days now takes 6 or 7, something has changed in how your body builds and sheds the uterine lining each month.
How Hormones Control Period Length
Your menstrual cycle runs on a tightly timed rise and fall of two hormones: estrogen and progesterone. Estrogen thickens the uterine lining in the first half of your cycle. After ovulation, progesterone stabilizes that lining and, when it drops, triggers a clean, predictable shed. That shed is your period.
When ovulation doesn’t happen in a given month, progesterone never enters the picture. Without it, estrogen keeps building the lining unchecked, making it thicker than normal. When that lining finally breaks down, there’s simply more tissue to shed, so bleeding lasts longer and tends to be heavier. The lining can also become unstable and leak irregularly, causing spotting that drags out for days before or after the main flow. This is one of the most common explanations for a period that suddenly seems to go on and on.
Skipped ovulation (called anovulation) isn’t rare. Stress, illness, significant weight changes, over-exercising, and polycystic ovary syndrome (PCOS) can all cause it. If your cycle length has also become unpredictable, that’s a strong clue that you’re not ovulating every month.
Perimenopause and Changing Cycles
If you’re in your 40s, perimenopause is a likely explanation. During this transition, the ovaries start producing less estrogen and may release an egg some months but not others. That inconsistency means your hormones no longer follow the same predictable pattern they did in your 20s and 30s.
The result is a period that can be shorter one month, longer the next, heavier, lighter, or missing entirely. Some cycles become noticeably longer in duration, with bleeding that stretches well past a week. The spacing between periods can shift too, sometimes arriving every 24 days, other times every 45. This phase typically begins in the mid-40s but can start earlier, and it lasts an average of 4 to 8 years before menopause.
Thyroid Problems
Your thyroid gland regulates the speed of many body functions, including your menstrual cycle. When the thyroid is underactive (hypothyroidism), it slows things down broadly, and that includes the hormonal signaling that controls how your uterine lining builds and sheds. The result is often heavier, longer periods alongside other symptoms like fatigue, weight gain, feeling cold, and dry skin. If your period has gotten longer and you’re also feeling sluggish or noticing other changes, a simple blood test can check your thyroid levels.
Your IUD or Other Medications
The type of IUD you have matters. Copper IUDs are well known for making periods heavier, longer, and crampier, especially in the first few months after insertion. This happens because copper triggers a local inflammatory response in the uterus. Hormonal IUDs tend to have the opposite effect over time, but they can cause irregular, drawn-out light bleeding during the first three to six months as your body adjusts.
Blood-thinning medications are another common culprit. A study published by the American Society of Hematology found that 66% of women taking blood thinners for blood clots experienced abnormally heavy uterine bleeding at some point during treatment, with the biggest increase occurring during the very first cycle after starting the medication. Aspirin, even at low doses, can have a similar effect because it reduces your blood’s ability to clot. If you’ve recently started any new medication and noticed your period getting longer, it’s worth flagging to your provider.
Uterine Fibroids and Polyps
Fibroids are noncancerous growths in or on the uterine wall, and they’re extremely common, affecting up to 80% of women by age 50. Not all fibroids cause symptoms, but those that grow into the uterine cavity or distort its shape can increase the surface area of the lining, leading to longer and heavier bleeding. Polyps, which are smaller growths on the inner lining itself, can have a similar effect by creating extra tissue that bleeds irregularly. Both are typically found through an ultrasound.
Bleeding Disorders
Sometimes a longer, heavier period points to a problem with how your blood clots rather than a problem with your uterus. Von Willebrand disease is the most common inherited bleeding disorder, and it’s significantly underdiagnosed in women. Among women with chronically heavy periods, between 5% and 24% turn out to have Von Willebrand disease. The condition makes it harder for blood to clot efficiently, so period bleeding lasts longer and is harder to control.
Clues that a bleeding disorder might be involved include a history of easy bruising, frequent nosebleeds, excessive bleeding after dental work or surgery, or a family member with similar issues. If that sounds familiar, specific blood tests can identify the condition.
Signs Your Bleeding Needs Attention
Not every long period is an emergency, but certain patterns cross a line. You should be evaluated if you experience any of the following:
- Soaking through a pad or tampon every hour for several hours in a row
- Needing to double up on pads to control the flow
- Waking up at night to change your pad or tampon
- Passing blood clots the size of a quarter or larger
- Bleeding past 7 days consistently
Heavy, prolonged bleeding can lead to iron deficiency anemia over time. If you’re feeling unusually tired, lightheaded, or short of breath alongside longer periods, low iron could be the reason.
How Longer Periods Are Treated
Treatment depends entirely on the cause. If skipped ovulation is the issue, hormonal birth control (the pill, patch, or hormonal IUD) can regulate your cycle by providing the progesterone your body isn’t making on its own. This thins the lining and gives you a shorter, lighter, more predictable bleed.
For people who don’t want hormonal options, there’s a medication that helps blood clot more effectively in the uterus. It’s taken as a tablet up to three times a day, only during the days of your period, for a maximum of 5 days per cycle. It doesn’t shorten the cycle itself but reduces how much you bleed during it.
Fibroids and polyps can sometimes be removed through minimally invasive procedures if they’re causing significant symptoms. Thyroid-related changes typically resolve once thyroid levels are corrected with medication. And if a bleeding disorder is identified, a hematologist can guide a treatment plan tailored to your specific condition.
Tracking your cycle for two or three months before an appointment gives your provider a clearer picture. Note how many days you bleed, how heavy the flow is each day, how many pads or tampons you go through, and whether you’re passing clots. That information helps narrow down the cause faster than a vague description of “longer periods.”