A period lasting two weeks is not normal, but it’s also not rare. A typical menstrual period lasts between three and seven days. Anything beyond eight days is classified as prolonged bleeding, and at two weeks, something is clearly disrupting your cycle. The causes range from harmless hormonal shifts to conditions that need treatment, so understanding the possibilities can help you figure out your next step.
Common Hormonal Causes
The most frequent reason for a prolonged period is a hormonal imbalance, specifically between estrogen and progesterone. These two hormones control how thick your uterine lining grows and when it sheds. When they fall out of sync, your lining may build up unevenly and then shed in a slow, drawn-out process instead of all at once over a few days.
This can happen for several reasons. Stress, significant weight changes, intense exercise, and illness can all throw off your cycle temporarily. If you recently stopped or started hormonal birth control, your body may need a few months to recalibrate. Skipping ovulation (called an anovulatory cycle) is another common trigger: without ovulation, your body doesn’t produce enough progesterone to signal the lining to shed efficiently, so bleeding becomes irregular and can drag on.
Thyroid Problems
Your thyroid gland plays a surprisingly large role in your menstrual cycle. An underactive thyroid (hypothyroidism) suppresses hormones your ovaries need to function properly, and it can change how your blood clots, leading to heavier, longer bleeding. It also causes the uterine lining to thicken excessively and then shed unpredictably. If your prolonged period comes with fatigue, weight gain, dry skin, or feeling cold all the time, a simple blood test can check your thyroid levels.
Perimenopause
If you’re in your late 30s or 40s, perimenopause is a likely explanation. During this transition, estrogen and progesterone rise and fall erratically. Your periods may get longer or shorter, heavier or lighter, and you may skip ovulation entirely some months. A two-week period during perimenopause isn’t unusual, but it still warrants a checkup to rule out other causes, especially if the bleeding is heavy.
Structural Causes in the Uterus
Sometimes the issue isn’t hormonal but physical. Growths inside the uterus can create extra surface area that bleeds, or they can interfere with the uterus’s ability to contract and stop bleeding on its own.
Fibroids
Uterine fibroids are noncancerous growths in or on the wall of the uterus. They’re extremely common, especially in women over 30. Fibroids that grow into the uterine cavity distort the lining and increase the amount of tissue that sheds each cycle, leading to prolonged and heavy periods. Small fibroids may cause no symptoms at all, while larger ones can cause pelvic pressure and pain along with extended bleeding.
Polyps
Endometrial polyps are soft overgrowths of the uterine lining. They’re estrogen-sensitive, meaning they grow in response to estrogen in your body. Polyps cause irregular bleeding, unpredictable periods, bleeding between periods, and heavy flow. Because they create extra tissue that sheds on its own schedule, they can easily extend a period beyond its normal length.
Adenomyosis
In adenomyosis, the tissue that normally lines the inside of the uterus grows into the muscular wall. During your period, that embedded tissue also thickens, breaks down, and bleeds, but it has nowhere to go. This causes the uterus to enlarge and leads to heavy, prolonged periods often accompanied by severe cramping. Adenomyosis is most common in women in their 30s and 40s and is sometimes confused with fibroids because the symptoms overlap.
IUDs and Birth Control
If you recently had a copper IUD inserted, prolonged bleeding in the first few months is a known side effect. Periods typically become 25 to 50 percent heavier after a copper IUD, and the first two to three cycles tend to be the worst. Some degree of bleeding or spotting is normal for the first several days after insertion, and irregular bleeding can continue for up to six months as your body adjusts.
Hormonal IUDs and other hormonal contraceptives can also cause breakthrough bleeding, particularly in the first three to six months. If you’ve just started a new pill, patch, or implant, extended spotting or light bleeding is common while your body adapts. This type of bleeding is usually lighter than a true period, though it can be hard to tell the difference when it lasts this long.
Signs That Bleeding Needs Urgent Attention
A two-week period always deserves a conversation with a healthcare provider, but certain signs mean you should be seen quickly. According to Cleveland Clinic guidelines, you should seek care if you experience any of the following:
- Soaking through two or more pads or tampons per hour for two to three consecutive hours
- Blood clots the size of a quarter or larger appearing more than once or twice
- Needing to wake up at night to change a pad or tampon
- Doubling up on protection, like using a tampon and a pad together, to prevent leaking
- Feeling dizzy, lightheaded, or short of breath, which may signal significant blood loss
How Prolonged Bleeding Leads to Anemia
Two weeks of bleeding can deplete your iron stores faster than your body can replace them. Iron is essential for making hemoglobin, the protein in red blood cells that carries oxygen. When iron drops too low, you develop iron deficiency anemia, and the symptoms can creep up gradually enough that you don’t realize how depleted you’ve become.
Watch for extreme tiredness that rest doesn’t fix, pale skin, a fast heartbeat or shortness of breath with normal activity, cold hands and feet, headaches, dizziness, and brittle nails. One unusual but telling sign is craving non-food items like ice, dirt, or clay. If you notice any of these, a blood test can confirm whether you’re anemic. Many women with heavy or prolonged periods benefit from iron supplementation even before their bleeding issue is fully resolved.
What Happens at the Doctor’s Office
When you see a provider about prolonged bleeding, expect them to start with a detailed history of your cycles: how long they last, how heavy they are, whether you’ve noticed changes, and what medications or contraceptives you use. Blood work typically comes next, checking your blood count for anemia, your thyroid function, and sometimes your hormone levels or clotting factors.
If a structural cause is suspected, the next step is usually a transvaginal ultrasound, which gives a detailed view of your uterus and can identify fibroids, polyps, and signs of adenomyosis. In some cases, a provider may recommend a procedure to look directly inside the uterus or take a small tissue sample from the lining to rule out abnormal cell growth. This is more common in women over 35 or those with risk factors.
Treatment depends entirely on the cause. Hormonal imbalances often respond to hormonal medications that regulate your cycle. Polyps and certain fibroids can be removed with minimally invasive procedures. Thyroid issues are managed with medication that brings your hormone levels back to normal, which usually corrects the bleeding pattern over time. For many women, getting a clear diagnosis brings significant relief, both because treatment works and because the uncertainty of not knowing is its own kind of stress.