A period lasting two weeks is not normal, and it usually signals that something is disrupting your hormonal balance or your uterine lining. A typical period lasts between three and seven days. Anything beyond seven days is classified as prolonged menstrual bleeding, and reaching the two-week mark means your body is telling you something worth investigating.
The causes range from harmless hormonal hiccups to conditions that need treatment. Here’s what could be behind it and what to expect if you get it checked out.
Hormonal Imbalance Is the Most Common Cause
Your menstrual cycle depends on a precise back-and-forth between estrogen and progesterone. Estrogen thickens the uterine lining in the first half of your cycle, and progesterone stabilizes it after ovulation. When you don’t ovulate in a given month, progesterone never rises. Without that signal, estrogen keeps building the lining until it becomes too thick to sustain itself and sheds unevenly, often for much longer than a normal period.
This kind of ovulatory dysfunction is one of the most frequent reasons for prolonged bleeding. It can happen to anyone, but certain situations make it more likely: high stress, significant weight changes, polycystic ovary syndrome (PCOS), and thyroid problems. An underactive thyroid in particular is linked to heavier, longer periods, while an overactive thyroid tends to make periods lighter or disappear altogether.
Perimenopause Changes the Rules
If you’re in your 40s, a two-week period may be related to perimenopause. During this transition, which can start a full decade before menopause, your ovaries begin producing less estrogen and don’t always release an egg each month. The result is unpredictable cycles. Some months your period may be shorter, lighter, or skip entirely. Other months it drags on much longer and comes with heavier flow than you’re used to.
This is common, but “common in perimenopause” doesn’t mean it should be ignored. Prolonged bleeding during this stage still warrants evaluation because it can also overlap with conditions like polyps or, less commonly, precancerous changes to the uterine lining that become more relevant with age.
Structural Problems Inside the Uterus
Sometimes the issue isn’t hormonal at all. Growths inside or on the uterus can physically interfere with how your lining sheds and how your uterus contracts to stop bleeding.
Polyps
Uterine polyps are small, soft growths that attach to the inner wall of the uterus. They’re sensitive to estrogen, meaning they grow in response to it. Polyps can cause irregular bleeding, very heavy flow, bleeding between periods, and periods that stretch well beyond the normal window. They’re usually noncancerous, but they don’t tend to resolve on their own.
Fibroids
Fibroids (also called leiomyomas) are muscular growths in the uterine wall. They’re extremely common, especially in your 30s and 40s. Not all fibroids cause symptoms, but the ones that grow near the inner lining of the uterus can increase the surface area that bleeds during your period and interfere with the uterus’s ability to clamp down and stop the flow. The result is heavier, longer periods.
Adenomyosis
In adenomyosis, tissue that normally lines the uterus grows into the muscular wall instead. This causes the uterus to enlarge and leads to prolonged, heavy, painful periods. It’s most common in women who’ve had children or are over 30, and it’s often underdiagnosed because its symptoms overlap with fibroids.
Bleeding Disorders and Other Medical Causes
About one in five women with chronically heavy or prolonged periods has an underlying bleeding disorder. The most common is von Willebrand disease, a condition where the blood doesn’t clot efficiently. If your periods have been consistently long and heavy since your very first cycle, or if you bruise easily, bleed a long time from cuts, or have had heavy bleeding after dental work or surgery, a clotting disorder is worth investigating.
Infections of the cervix or uterus, including sexually transmitted infections like chlamydia, can also cause irregular or prolonged bleeding. So can certain medications. Hormonal IUDs sometimes cause extended spotting in the first few months after insertion. Blood thinners, some antidepressants, and even switching or missing doses of hormonal birth control can all trigger a longer-than-expected period.
One cause that’s easy to overlook: early pregnancy complications. A very early miscarriage or an ectopic pregnancy can produce bleeding that feels like a long, unusual period. Pregnancy is actually the most common cause of unexpected uterine bleeding in people of reproductive age, which is why a pregnancy test is typically the first thing checked.
What Happens When You Get It Evaluated
If you see a provider about a two-week period, the process usually starts with blood work. A pregnancy test comes first. From there, expect tests that check your thyroid function, iron levels (to see if the bleeding has made you anemic), and possibly your clotting ability. If PCOS is suspected, hormone levels including testosterone may be tested.
Imaging is the next step for many people. A pelvic ultrasound can reveal fibroids, measure the thickness of your uterine lining, and flag anything unusual about the shape of your uterus. If polyps are suspected, a more detailed version called sonohysterography uses a small amount of saline inside the uterus to give a clearer picture and distinguish polyps from fibroids.
In some cases, particularly if you’re over 35 or the bleeding pattern is concerning, an endometrial biopsy may be recommended. This samples a small portion of the uterine lining to check for precancerous or abnormal cells. It’s a quick in-office procedure, uncomfortable but brief.
How Prolonged Bleeding Is Treated
Treatment depends entirely on the cause, which is why the diagnostic step matters so much. For hormonal imbalances and ovulatory dysfunction, hormonal birth control is often the first-line option. The pill, a hormonal IUD, or other hormonal methods work by regulating the buildup and shedding of the uterine lining, which shortens periods and lightens flow. For people who can’t or don’t want to use hormonal methods, a medication that helps blood clot more effectively at the uterine lining can reduce both the duration and heaviness of bleeding.
Polyps are typically removed through a minor procedure done through the cervix with a small camera. Fibroids have a wider range of treatment options depending on their size, number, and location, from medication to shrink them to surgical removal. Adenomyosis can be managed with hormonal treatments or, in severe cases, surgery. Thyroid problems are treated with thyroid medication, which often normalizes periods as a side effect. Bleeding disorders are managed with targeted therapies through a hematologist.
Signs That Need Urgent Attention
A two-week period is worth a scheduled appointment, but certain symptoms alongside it call for faster action. Soaking through a pad or tampon every hour for several consecutive hours is a red flag for significant blood loss. Passing blood clots the size of a quarter or larger, feeling dizzy or lightheaded, experiencing shortness of breath, or feeling unusually exhausted can all point to anemia from the bleeding. If you’re going through pads so quickly that it’s interfering with your daily life, or if you feel faint, that’s a same-day call rather than a wait-and-see situation.
Even without those acute symptoms, any period lasting two weeks deserves investigation. It may turn out to be a one-time hormonal blip, especially after a stressful month or a skipped ovulation. But it can also be the first visible sign of a treatable condition that will keep causing problems until it’s addressed.