A normal period lasts about four to five days, with most people losing only two to three tablespoons of blood total. Anything that stretches beyond seven days is considered prolonged, and it usually signals that something specific is going on with your hormones, your uterus, or sometimes a new medication or device. The good news is that most causes are treatable once identified.
What Counts as Too Long
There’s a wide range of normal. Some people consistently have three-day periods, others go six days, and both are fine. The threshold that matters is seven days. If your period regularly exceeds a week, or if a period that used to be four days is now lasting seven or eight, that shift is worth paying attention to. A single longer-than-usual cycle can happen for mundane reasons like stress, travel, or a bad night’s sleep throwing off ovulation. But when it becomes a pattern over two or three cycles, there’s likely an underlying cause.
Hormonal Reasons Your Period Got Longer
The most common explanation for a longer period is a hormonal imbalance, specifically not enough progesterone. Here’s what happens: during a normal cycle, your ovaries release an egg, which triggers progesterone production. Progesterone keeps your uterine lining organized and controls how it sheds. When ovulation doesn’t happen (a skipped release called anovulation), progesterone stays low, the lining builds up too thick, and when it finally sheds, bleeding is heavier and drags on longer.
Several conditions create this pattern:
- Polycystic ovary syndrome (PCOS): Insulin resistance and excess androgens interfere with regular ovulation, leading to unpredictable, prolonged periods.
- Thyroid problems: Both underactive and overactive thyroid can disrupt the hormonal signals that regulate your cycle.
- Perimenopause: In the years before menopause, typically starting in your 40s, fluctuating hormone levels make cycles increasingly irregular. Longer, heavier periods are one of the hallmark signs.
- Obesity: Fat tissue produces estrogen, and excess estrogen without enough progesterone to balance it causes the uterine lining to over-thicken.
Teenagers in their first year of menstruation also commonly experience longer periods because their bodies haven’t yet settled into a regular ovulation pattern. This is normal and usually resolves on its own within a year or two.
Structural Problems in the Uterus
Sometimes the issue isn’t hormonal at all. Growths inside or on the uterus can physically change how the lining sheds. Uterine fibroids, which are noncancerous muscle growths, are especially common. Fibroids that grow just beneath the inner lining of the uterus (submucosal fibroids) are the type most likely to cause heavy, prolonged bleeding because they distort the surface where the lining attaches. Larger fibroids can also cause bleeding between periods and significant pain.
Uterine polyps, which are small overgrowths of the lining tissue itself, work similarly. They create extra surface area that bleeds, and they can prevent the uterus from contracting efficiently to stop the flow. Both fibroids and polyps become more common with age but can appear at any point during your reproductive years.
Medications and Devices That Affect Bleeding
If your period got longer shortly after starting something new, that’s a strong clue. The copper IUD is one of the most well-known culprits. Unlike hormonal IUDs, the copper version works by creating inflammation in the uterus, which prevents pregnancy but also tends to make periods heavier and longer, especially in the first three to six months after insertion. For many people these side effects ease up over time, but for some they persist.
Blood thinners, certain anti-inflammatory medications, and even switching between different types of hormonal birth control can temporarily change your bleeding pattern. If the timing lines up with a new prescription or device, that’s worth mentioning to your provider.
Signs That Need Prompt Attention
A period that’s a day or two longer than usual for one cycle is rarely an emergency. But certain signs mean you should get evaluated sooner rather than later. Bleeding through two or more pads or tampons per hour for two to three consecutive hours is a red flag that warrants same-day medical attention. Other warning signs include feeling dizzy or lightheaded, having a racing heartbeat, or noticing that your skin looks unusually pale. These can indicate you’re losing enough blood to affect your circulation.
Even without dramatic symptoms, consistently heavy or prolonged periods quietly drain your iron stores. Over months, this leads to iron-deficiency anemia, which causes fatigue, brain fog, shortness of breath during exercise, and brittle nails. Many people assume they’re just tired or out of shape when the real problem is that their period has been slowly depleting their iron for months.
How the Cause Gets Identified
If you go in for evaluation, your provider will typically start with blood work to check your hormone levels, thyroid function, and iron stores. If there’s any concern about a bleeding disorder (which is more common than most people realize), specific tests can check for conditions like von Willebrand disease, a genetic condition that impairs clotting.
A pelvic ultrasound is the standard imaging tool for spotting fibroids, polyps, or other structural issues. For people over 45, or younger people with certain risk factors like obesity or PCOS, a small tissue sample from the uterine lining may be taken to rule out abnormal cell growth. This is a quick in-office procedure, not surgery.
Treatment Options That Work
Treatment depends entirely on what’s driving the longer periods, which is why getting the right diagnosis matters.
For hormonal imbalances, hormonal birth control is often the first approach. The pill, hormonal IUD, or other methods supply the progesterone your body isn’t making on its own, which thins the uterine lining and shortens bleeding. For people who can’t or don’t want to use hormonal methods, a medication that helps blood clot more efficiently can reduce menstrual blood loss by 40 to 65 percent. It’s taken only during the days you’re actually bleeding, not every day of the month.
For fibroids, treatment scales with the severity. Small fibroids that cause mild symptoms might just be monitored. Larger or more troublesome ones can be treated with a procedure that blocks the blood supply to the fibroid, causing it to shrink, or with surgical removal of the fibroid itself. Both options preserve the uterus. Polyps are usually removed in a straightforward outpatient procedure.
If the copper IUD is the issue and symptoms haven’t improved after three to six months, switching to a hormonal IUD or a different contraceptive method typically resolves the problem. The hormonal IUD, in contrast to the copper version, often makes periods lighter and shorter.
Tracking What’s Happening
Before your appointment, it helps to track a few cycles in detail. Note the start and end date of each period, how many pads or tampons you use per day, whether you’re passing clots (and roughly how large), and any pain or other symptoms. This gives your provider concrete information to work with instead of a vague “it seems longer.” Most period-tracking apps let you log flow intensity, which makes this easy. Even jotting it down on a calendar works. Two to three months of data is usually enough to see a clear pattern.