Heavy periods happen when something causes your uterine lining to build up too thick, your body has trouble stopping the bleeding once it starts, or a growth inside the uterus creates extra surface area that bleeds. Sometimes it’s a combination of all three. If you’re soaking through a pad or tampon every hour or two for several hours straight, bleeding longer than seven days, passing clots the size of a quarter or larger, or doubling up on pads, your flow qualifies as genuinely heavy, not just an inconvenience.
How Hormones Control Your Flow
Your period’s heaviness starts with what happens in the weeks before bleeding begins. During the first half of your cycle, estrogen tells the uterine lining to grow and thicken in preparation for a potential pregnancy. After ovulation, progesterone steps in to stabilize that lining. If no pregnancy occurs, both hormones drop, and the lining sheds in a controlled way.
Problems arise when this balance tips. If you don’t ovulate in a given month, your body never produces the progesterone needed to keep the lining in check. Estrogen continues building the lining unopposed, and it keeps getting thicker. When it finally sheds, there’s simply more tissue and more blood vessels to break down, which means a heavier, often longer period. This is the single most common hormonal explanation for heavy bleeding, and it can happen to anyone who occasionally skips ovulation, whether from stress, polycystic ovary syndrome, thyroid issues, or approaching menopause.
Fibroids and Polyps
Structural growths inside the uterus are another major culprit. Uterine polyps are soft, finger-like growths that form when cells in the uterine lining overgrow. They’re estrogen-sensitive, meaning they grow in response to the same hormone that thickens your lining each month. They attach to the uterine wall by a stalk or a broad base, and they increase the surface area that bleeds during your period.
Fibroids work differently. These are firm, muscular growths in the wall of the uterus. When they push into the uterine cavity or distort its shape, they can prevent the uterus from contracting effectively to slow bleeding. They can also stretch the lining over a larger area. Both polyps and fibroids are extremely common and usually noncancerous, but they can make periods dramatically heavier without causing any other obvious symptoms between cycles.
Bleeding Disorders You Might Not Know About
Some people bleed heavily because their blood doesn’t clot normally. Von Willebrand disease is the most common inherited bleeding disorder, affecting up to 1% of the population. Among women who have it, heavy menstrual bleeding is the number one symptom, reported by 93 to 95% of those diagnosed. Yet there’s often a gap of about 16 years between when symptoms start and when a diagnosis is actually made. Women with the condition report an average of six different bleeding symptoms before anyone identifies the underlying problem.
If your heavy periods have been a lifelong pattern rather than something that started recently, and you also bruise easily, get frequent nosebleeds, or bleed a lot after dental work or minor injuries, a blood-clotting disorder is worth investigating. These conditions are underdiagnosed partly because heavy periods get normalized, and partly because the lab tests sometimes need to be repeated more than once to catch the issue.
Why Periods Get Heavier in Your 40s
Perimenopause, the transition years leading up to menopause, is notorious for changing bleeding patterns. Your ovaries begin producing less estrogen overall, but the bigger issue is inconsistency. Some months you ovulate, some months you don’t. The months you skip ovulation, estrogen builds the lining without progesterone ever arriving to regulate it. The result can be surprisingly heavy, prolonged, or unpredictable periods alternating with lighter ones.
Polyps and a condition called endometrial hyperplasia (where the lining grows abnormally thick) also become more common during this stage. Because the risk of endometrial cancer rises with age, new or worsening heavy bleeding after 40 typically warrants more thorough evaluation than it would in a 25-year-old.
The Iron Problem
Heavy periods don’t just feel miserable in the moment. Over months and years, they drain your iron stores. Iron deficiency anemia is one of the most common consequences, and its symptoms often creep in so gradually that you attribute them to something else: extreme tiredness, weakness, feeling cold all the time, dizziness, headaches, a fast heartbeat with minimal exertion, or brittle nails.
Some people develop unusual cravings for ice, dirt, or non-food items, a phenomenon called pica. Others notice restless legs at night or an oddly sore tongue. These are all signs your body is running low on the iron it needs to carry oxygen through your blood. If any of this sounds familiar alongside your heavy periods, a simple blood test can confirm whether your iron levels have dropped.
How Heavy Periods Are Evaluated
Figuring out the cause usually starts with blood work to check for anemia, thyroid problems, and clotting issues. An ultrasound of your uterus and ovaries can reveal fibroids, polyps, or other structural changes. In some cases, your doctor may recommend an endometrial biopsy, where a small tissue sample is taken from the uterine lining to rule out abnormal cell growth.
If initial tests don’t explain the bleeding, a sonohysterography (where fluid is used to get a clearer ultrasound picture of the lining) or a hysteroscopy (where a thin camera is inserted to look directly inside the uterus) can catch smaller polyps or other issues that a standard ultrasound might miss. Keeping a diary of your flow for a few cycles, noting how many pads or tampons you go through and how often you change them, gives your provider concrete information to work with.
Treatment Options That Work
Treatment depends on the cause, but the most effective options fall into two categories: medications that reduce bleeding and hormonal treatments that thin the lining.
A medication that helps blood clot more effectively at the uterine lining can reduce menstrual blood loss by 34 to 65% within a few cycles. You take it only during your period, and it works by preventing the normal breakdown of clots that form as the lining sheds. It’s a good option if you want to keep your natural cycle and don’t need contraception.
A hormonal IUD that releases a small amount of progestin directly into the uterus is consistently the most effective nonsurgical treatment. It thins the lining dramatically, and many people find their periods become very light or stop altogether. Studies have found it outperforms other medical treatments for heavy bleeding. Hormonal birth control pills or other progestin-based options can also help by suppressing lining growth, though the IUD delivers the hormone right where it’s needed with fewer body-wide effects.
When fibroids or polyps are the cause, removing them often resolves the heavy bleeding directly. For people who are done having children and haven’t responded to other treatments, procedures that remove or destroy the uterine lining, or in some cases the uterus itself, are options that provide a permanent solution.