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Published by Floriva · Updated 2026-04-28 · How Floriva checks its guides

Heavy Period Bleeding: Causes and When to See a Doctor

Heavy menstrual bleeding can stem from fibroids, adenomyosis, hormonal imbalances, or bleeding disorders. Learn what to track and when to seek evaluation.

Heavy menstrual bleeding, soaking through a pad or tampon every hour for several consecutive hours, or passing clots larger than a quarter, is a clinical finding with several possible causes, including fibroids, adenomyosis, hormonal imbalances, thyroid dysfunction, and bleeding disorders. Tracking volume and duration accurately is the first step toward useful clinical evaluation.

Defining Heavy Period Bleeding

Heavy menstrual bleeding is both common and commonly undertreated. Many people assume that very heavy periods are simply their normal, particularly if heaviness has been consistent since adolescence. But heavy bleeding that disrupts daily life, requiring constant pad or tampon changes, causing leaks despite protection, or producing large clots, is a clinical finding worth investigating. It is not a baseline to accept.

The clinical threshold for heavy menstrual bleeding is often described as more than 80 milliliters of blood loss per cycle, but this is not a practical measurement at home. More useful markers are behavioral: Do you soak through protection every hour for several consecutive hours? Do you need to get up at night to change? Do you use both a pad and a tampon? Do you pass clots larger than a quarter?

If any of those describes your experience regularly, this guide is relevant to you.

This guide is for educational purposes only and is not a substitute for medical advice.

What Causes Heavy Period Bleeding

Uterine Fibroids

Fibroids are noncancerous growths of the uterine muscle wall. They are among the most common causes of heavy periods. Submucosal fibroids sit close to the uterine cavity. They have the most direct impact on bleeding: they can distort the shape of the uterine lining and interfere with the normal contraction mechanism that limits bleeding. Even fibroids that cause no pain can produce significant increases in flow.

Adenomyosis

Adenomyosis occurs when uterine lining tissue grows into the muscle of the uterine wall. The uterus enlarges and becomes less able to contract efficiently during menstruation, leading to heavier and often more painful periods. Adenomyosis is frequently underdiagnosed because it shares symptoms with fibroids and endometriosis, and diagnosis requires imaging or biopsy.

Hormonal Imbalance

Estrogen drives uterine lining growth. When estrogen is elevated relative to progesterone, whether from anovulatory cycles, PCOS, perimenopause, or obesity, the lining builds thicker than usual, resulting in heavier bleeding when it sheds. Thyroid dysfunction, both hypothyroid and hyperthyroid states, can also alter menstrual flow.

Uterine Polyps

Endometrial polyps are soft tissue growths attached to the inner uterine wall. They can cause heavy or irregular bleeding, spotting between periods, or postmenopausal bleeding. Most are benign but can occasionally harbor abnormal cells.

Bleeding Disorders

Von Willebrand disease, a disorder affecting platelet function and clotting, frequently presents as heavy menstrual bleeding. It is often not diagnosed until adolescence or adulthood precisely because heavy periods are normalized. If heavy periods began at your very first cycle and have been consistent since, asking your provider to screen for a bleeding disorder is reasonable.

Copper IUD

The copper intrauterine device (Paragard and similar) increases menstrual flow in many users, particularly in the months following insertion. This effect is a known trade-off and varies in magnitude between individuals.

Anovulatory Cycles and Perimenopause

When ovulation does not occur, progesterone does not rise to its usual post-ovulatory level. Estrogen continues stimulating the uterine lining unchecked until it eventually breaks down, sometimes resulting in breakthrough bleeding that is heavier or more irregular than a typical period. Anovulatory cycles are more frequent during perimenopause, PCOS, and periods of significant hormonal disruption.

How to Track Bleeding Volume

Objective tracking of menstrual flow gives a provider more to work with than estimates from memory. Useful metrics:

Product type and change frequency: note whether you use regular or super pads/tampons/discs, and how often you change them
Soaking pattern: does the product fill completely before you change it
Clots: size and frequency (smaller than a dime, quarter-sized, larger)
Days of heaviest flow: which day of the period is heaviest, and how many days total qualify as heavy
Night protection: do you wake up to change protection at night
Period length: first day to last day
Leaks: any episodes of leaking through clothing despite protection

This information does not need to be perfectly precise. A consistent logging method applied across several cycles reveals patterns that matter clinically.

When to See a Healthcare Provider

Seek evaluation if:

You soak through a pad or tampon every hour for two or more consecutive hours
Your period regularly lasts more than seven days
You pass clots larger than a quarter
Bleeding is significantly interfering with daily activities, work, or sleep
You have symptoms of anemia: unusual fatigue, shortness of breath, feeling cold constantly
You have started a new contraceptive method and bleeding has significantly worsened
Your bleeding pattern has changed substantially compared to your baseline

Seek prompt medical attention if you are soaking through more than one pad per hour and the bleeding does not slow, you are lightheaded or faint, or you have significant pelvic pain alongside heavy bleeding.

A Note on Heavy Bleeding Data and Privacy

Logging menstrual flow, including heavy bleeding, clot size, and cycle duration, is medically meaningful information that also carries personal sensitivity. In the current legal landscape, detailed reproductive health data stored on company servers can be subpoenaed in states where abortion is criminalized.

Flo Health was subject to an FTC enforcement action in 2021 for sharing health and period data with Facebook and Google. A $59.5 million class action settlement followed in 2025. This data is not covered by HIPAA.

On-device trackers like Floriva, Drip, and Euki store your flow logs on your device only. No company server holds the data, which means there is nothing to compel, breach, or share with a third party.

Definitions

Menorrhagia: The clinical term for heavy or prolonged menstrual bleeding. A period lasting more than seven days, or total blood loss exceeding 80 milliliters per cycle, meets the clinical threshold, though this measurement is practical only in clinical settings. A more usable benchmark is whether bleeding significantly interferes with daily life.
Uterine fibroids: Noncancerous growths in or on the uterine wall. They are very common and often cause no symptoms. Submucosal fibroids, those closest to the uterine cavity, are most likely to cause heavy bleeding by distorting the uterine lining or disrupting normal contraction.
Adenomyosis: A condition in which uterine lining tissue grows into the muscular wall of the uterus, causing the uterus to enlarge. It commonly causes heavy, prolonged, painful periods and is a significant and underdiagnosed cause of heavy menstrual bleeding.
Anovulatory bleeding: Bleeding that results from cycles in which ovulation does not occur. Without ovulation, progesterone is absent and estrogen continues to stimulate uterine lining growth unopposed, which can eventually result in breakthrough bleeding that is often irregular and sometimes heavy.
von Willebrand disease: The most common inherited bleeding disorder, affecting the clotting factor von Willebrand factor. Heavy menstrual bleeding is frequently the presenting symptom and the condition is underdiagnosed. It is worth asking about if heavy periods began at menarche and persist without other identified causes.

Quick answers to the obvious questions.

What counts as heavy period bleeding?

A practical definition: soaking through a pad or tampon every hour for two or more consecutive hours, needing to use both a pad and a tampon simultaneously, passing blood clots larger than a quarter, or having a period that lasts longer than seven days. If bleeding regularly interferes with daily activities, that is a clinically relevant signal regardless of whether a formal volume threshold is met.

What causes heavy periods?

Common causes include uterine fibroids, adenomyosis, hormonal imbalance (particularly estrogen-progesterone ratio), thyroid dysfunction, polycystic ovary syndrome, anovulatory cycles, uterine polyps, a copper IUD, and bleeding disorders like von Willebrand disease. In some cases no structural cause is found and the diagnosis is dysfunctional uterine bleeding or abnormal uterine bleeding of unknown cause.

Can heavy periods be a sign of something serious?

In most cases, heavy periods have benign though often treatable causes. Fibroids, adenomyosis, and hormonal factors are the most common. Uterine cancer can cause abnormal or heavy bleeding, but it is less common and more typically presents with irregular bleeding, postmenopausal bleeding, or bleeding between periods. Any significant change in your bleeding pattern warrants evaluation.

Is heavy bleeding normal after stopping hormonal birth control?

Some people experience temporarily heavier periods after stopping hormonal contraceptives, particularly after being on methods that significantly thinned the uterine lining. This typically normalizes within a few cycles. Persistently heavy bleeding more than three cycles after stopping hormonal contraception is worth discussing with a provider.

Questions people ask before they switch.

Can large blood clots during a period be normal?

Small clots (smaller than a dime) during heavy-flow days are common and not usually concerning. Clots larger than a quarter, especially if they are frequent, indicate that flow is heavy enough to prevent the clotting factors from fully breaking down the blood before it exits. This is worth documenting and discussing with a provider.

Can anemia result from heavy periods?

Yes. Chronic heavy menstrual bleeding is a leading cause of iron-deficiency anemia. Symptoms include fatigue, weakness, shortness of breath, difficulty concentrating, and cold intolerance. If you regularly have heavy periods and also feel chronically tired, asking your provider to check iron levels and a complete blood count is reasonable.

Does a copper IUD cause heavy periods?

Yes. Copper IUDs (like the Paragard) often cause heavier periods, particularly in the first few months after insertion. This is a well-documented side effect and typically improves but may not fully resolve. If you inserted a copper IUD and your periods became significantly heavier, this is likely device-related.

Can heavy periods be treated without surgery?

Yes. Hormonal treatments, including hormonal IUDs, oral contraceptives, progestins, and tranexamic acid, can significantly reduce menstrual flow. NSAIDs also reduce flow and cramping when taken at the start of the period. Surgical options exist for structural causes like fibroids or polyps. A provider can help identify which approach suits the underlying cause.