Heavy periods are one of the most common reasons people visit a gynecologist, and they almost always have an identifiable cause. Whether the culprit is a hormonal imbalance, a structural change in your uterus, or an underlying health condition, unusually heavy bleeding is your body signaling that something is off. The good news is that most causes are treatable once identified.
How to Tell If Your Bleeding Is Actually Heavy
It can be hard to know what counts as “too much” when you have nothing to compare against. The CDC defines heavy menstrual bleeding as soaking through one or more pads or tampons every hour for several hours in a row, or needing to change your pad or tampon after less than two hours. Bleeding that lasts longer than seven days per period also qualifies. Passing blood clots larger than a quarter is another reliable sign.
If you find yourself doubling up on protection (wearing a pad and a tampon at the same time), waking up at night to change, or skipping activities because you’re worried about leaking, your periods are likely heavier than they should be. These aren’t just inconveniences. Chronic heavy bleeding drains your iron stores over time, and ferritin levels below 30 μg/L indicate iron deficiency. That can leave you exhausted, short of breath, dizzy, and mentally foggy even when you’re not on your period.
Hormonal Imbalances
The most common reason for heavy periods is a hormonal imbalance between estrogen and progesterone. During a normal cycle, estrogen thickens your uterine lining in the first half, then progesterone stabilizes it after ovulation. When you don’t ovulate, which can happen during stress, with polycystic ovary syndrome (PCOS), during perimenopause, or even occasionally in otherwise healthy cycles, your body never produces that progesterone surge. Without it, estrogen keeps building the lining unchecked. When that thicker-than-normal lining finally sheds, the result is heavier, longer, and often irregular bleeding.
This pattern is especially common at two points in life: the first few years after your period starts and the years leading up to menopause. Both are times when ovulation is less predictable. But it can happen at any age, particularly if you have PCOS or other conditions that disrupt ovulation.
Fibroids, Polyps, and Adenomyosis
Structural changes inside the uterus are another major cause of heavy bleeding, and they’re remarkably common. Fibroids are noncancerous growths in the muscular wall of the uterus. They range from the size of a seed to the size of a grapefruit, and the ones that grow closest to the inner lining tend to cause the most bleeding. Polyps are smaller, finger-like growths on the lining itself that can bleed between periods as well as during them.
Adenomyosis is a condition where tissue similar to the uterine lining starts growing into the muscular wall of the uterus. This causes the uterus to thicken and enlarge, sometimes to double or triple its usual size. The hallmark symptoms are heavy bleeding with clotting and significant cramping. Adenomyosis is often underdiagnosed because it doesn’t always show up clearly on imaging, but it’s a well-recognized cause of periods that feel like they’re getting progressively worse over time.
Thyroid Problems and Bleeding Disorders
Sometimes the cause isn’t in your uterus at all. An underactive thyroid (hypothyroidism) can trigger heavy periods through several pathways at once. It impairs your blood’s ability to clot normally by causing platelet dysfunction, sometimes mimicking a condition called acquired von Willebrand syndrome. It also disrupts the hormonal signals between your brain and ovaries. When thyroid hormone levels drop low enough, the resulting hormonal cascade can raise estrogen levels while suppressing ovulation, creating the same unopposed estrogen pattern described above. Thyroid problems are easily detected with a blood test, and treating the thyroid issue often resolves the heavy bleeding.
Inherited bleeding disorders are another overlooked cause. Von Willebrand disease, the most common inherited bleeding disorder, affects up to 1 in 100 people and is significantly underdiagnosed in women. ACOG recommends that bleeding disorders be considered in anyone being evaluated for heavy periods, regardless of age. You’re at higher risk if your periods have been heavy since your very first one, or if you also experience frequent nosebleeds, easy bruising, prolonged bleeding after dental work, or a family history of bleeding problems. If any of those apply, it’s worth asking specifically about testing before starting hormonal treatment, since birth control pills can mask the lab results used to diagnose von Willebrand disease.
Other Common Triggers
Copper IUDs (the non-hormonal kind) are a well-known cause of heavier periods, particularly in the first three to six months after insertion. Blood-thinning medications, including daily aspirin, can increase menstrual flow. Certain supplements like fish oil and vitamin E have mild blood-thinning effects that some people notice during their periods. Rapid weight changes, extreme exercise, and significant stress can all shift your hormonal balance enough to change your bleeding pattern.
In rare cases, heavy bleeding can signal something more serious, including endometrial hyperplasia (an overgrowth of the uterine lining that can become precancerous) or uterine cancer. This is more of a concern for people over 45, those with a long history of irregular cycles, or those with risk factors like obesity or a family history. An ultrasound and sometimes a biopsy of the lining can rule these out.
Treatment Options That Work
Treatment depends entirely on what’s causing the bleeding, which is why getting a proper evaluation matters. But there are effective options across the board.
Hormonal Approaches
A hormonal IUD is one of the most effective treatments available. It releases a small amount of progestin directly into the uterus, thinning the lining and reducing blood loss by 80 to 90 percent. About 20 to 40 percent of users stop having periods entirely within the first year. It works well for hormonal imbalances, adenomyosis, and even small fibroids. Birth control pills, the hormonal patch, and the hormonal shot can also regulate bleeding by providing the progesterone your body may be missing.
Non-Hormonal Medications
If you prefer to avoid hormones, tranexamic acid is a prescription medication taken only during your period that helps your blood clot more effectively. In a randomized controlled trial published through the CDC, women taking it saw a 40 percent reduction in menstrual blood loss compared to just 8 percent in the placebo group. Anti-inflammatory medications like ibuprofen can also reduce flow, with the added benefit of easing cramps. Both work best when started at the very beginning of your period.
Procedures for Structural Problems
Fibroids and polyps can often be removed through minimally invasive procedures. Endometrial ablation, which destroys the uterine lining, is another option for people who are done having children. Recovery is roughly 19 days faster than with hysterectomy, and satisfaction rates are high. However, about 13 percent of people who have ablation eventually need further surgery. Hysterectomy is the only treatment that permanently eliminates menstrual bleeding, and quality of life scores tend to be slightly higher two years out compared to ablation. It’s typically reserved for cases where other treatments haven’t worked or when the underlying cause (like large fibroids or severe adenomyosis) warrants it.
What to Pay Attention To
Track your periods for two or three cycles before your appointment. Note how many pads or tampons you use per day, how often you change them, whether you pass clots, and how many days the bleeding lasts. This information is far more useful to a clinician than a vague description of “heavy.” Also note any bleeding between periods, bleeding after sex, or significant pain, as these details help narrow the diagnosis.
If you’re soaking through a pad or tampon every hour for more than two hours straight, feel lightheaded or faint, or notice your heart racing, those are signs of acute blood loss that need prompt attention. Chronic heavy periods that go untreated for months or years can lead to iron deficiency anemia severe enough to affect your heart, your concentration, and your daily functioning. The fix is often straightforward once the cause is identified.