Talk to a doctor about heavy periods if bleeding soaks through a pad or tampon every hour for several hours in a row, lasts longer than 7 days, includes clots larger than about a quarter, or leaves you tired, dizzy, or short of breath. You should also go if your periods have become heavier than your own normal, or if heavy bleeding is limiting work, exercise, sleep, or social plans. You do not need to hit a medical threshold for the problem to be worth raising, because heavy periods are common, often treatable, and frequently dismissed for years.
This guide explains what counts as heavy, what to track, common causes, what a visit usually involves, the treatment options clinicians commonly discuss, and which signs mean you should seek care urgently.
What counts as heavy
Clinically, heavy menstrual bleeding is often defined as losing more than about 80 mL of blood in a cycle, or having periods that last longer than 7 days. Few people measure blood in millilitres, so in practice the signs below are more useful. They match the symptoms the Mayo Clinic lists:
- Soaking through a pad or tampon every hour for several hours in a row
- Needing to double up, such as a tampon plus a pad
- Waking at night to change protection
- Passing blood clots larger than about a quarter
- Bleeding that lasts longer than 7 days
- Avoiding activities or planning your life around your period
- Symptoms of low iron: fatigue, weakness, pale skin, shortness of breath, dizziness, brittle nails, or unusual hair shedding
A typical period lasts about 2 to 7 days, with cycles of roughly 21 to 35 days. Heavy bleeding is not simply “worse cramps,” though the two can occur together.
Why heavy periods are so often normalized
Many people grow up assuming that very heavy periods are just how their body works, especially if a mother or sister has the same pattern. Gradual changes are also easy to miss. A period that slowly gets heavier over a few years can feel normal in the moment. But because heavy bleeding can cause iron deficiency and can have an underlying cause, it deserves evaluation even when you are used to it.
The question is not only how a period looks on paper, but how it affects your life. Missing school or work, leaking through clothes, or being constantly exhausted are good enough reasons to book a visit.
Common causes
| Cause | What it is | Other clues |
|---|---|---|
| Hormonal imbalance or irregular ovulation | The uterine lining builds up more than usual | Irregular cycles, common in puberty, PCOS, and perimenopause |
| Uterine fibroids | Non-cancerous growths in the uterus | Pelvic pressure, frequent urination, longer periods |
| Endometrial polyps | Small growths in the uterine lining | Bleeding between periods |
| Adenomyosis | Uterine lining tissue growing into the uterine wall | Heavy, painful periods |
| Endometriosis | Tissue like the uterine lining outside the uterus | Severe pain, pain during sex, fertility difficulty |
| Bleeding disorders | Such as von Willebrand disease | Heavy periods since the first period, easy bruising, nosebleeds, prolonged bleeding after dental work |
| Thyroid disease | Underactive thyroid can make periods longer and heavier | Fatigue, weight change, feeling cold |
| Copper IUD | A non-hormonal contraceptive that can increase flow | Starts after insertion |
| Medications | Blood thinners and some others | Check with the prescriber |
| Pregnancy complications | Including miscarriage or ectopic pregnancy | A missed period or positive test |
| Less common: overgrowth or cancer of the uterine lining | Changes in the lining | More likely with bleeding after menopause or in later reproductive years, which is why persistent abnormal bleeding gets checked |
Often a cause is found, but sometimes none is, and treatment can still help.
When to book a regular appointment
Make an appointment if any of these apply:
- Your period has become noticeably heavier or longer than your usual pattern.
- You regularly soak through protection in 1 to 2 hours or pass large clots.
- Periods regularly last more than 7 days.
- You bleed between periods, after sex, or more often than every 21 days.
- You feel tired, weak, or light-headed in a way that is new.
- Heavy bleeding has been there since your first periods, with easy bruising or nosebleeds as well.
- You are in your 40s or older and your bleeding pattern is changing. Perimenopause can cause heavy or irregular bleeding, as described in what menopause actually feels like, but a clinician should still confirm the cause.
- You have severe pain that does not respond to usual pain relief.
When to seek urgent care
Go to an emergency department or call your local emergency number if you have:
- Bleeding that soaks through at least one pad or tampon an hour for more than 2 hours in a row
- Dizziness, fainting, a very fast heartbeat, chest pain, or shortness of breath alongside heavy bleeding
- Heavy bleeding while pregnant, or heavy bleeding with severe one-sided pain
- Heavy bleeding with fever, or a very weak or pale appearance
- Passing tissue or very large clots along with severe pain
Any vaginal bleeding after menopause, meaning 12 or more months without a period, should be evaluated promptly, even if it is light.
How to prepare for the visit
A short record makes the appointment faster and more useful. Over 2 to 3 cycles, note:
- The first and last day of each period
- How many pads or tampons you use per day and how often you change them overnight
- The size of clots
- Any bleeding between periods
- Pain level and what you take for it
- Fatigue, dizziness, or other symptoms
- Medications and supplements, including blood thinners and aspirin
- Family history of heavy bleeding, bleeding disorders, fibroids, or endometriosis
The tips in the guide to tracking your cycle apply here too, and a simple calendar works. Some clinicians use a pictorial chart that scores how saturated each pad or tampon is.
What a medical evaluation usually involves
Expect questions about your cycle, bleeding pattern, pain, pregnancy possibility, and family history. Common next steps include:
- Physical and pelvic exam
- Blood tests: A complete blood count and ferritin level to check for anemia and iron stores, and sometimes thyroid tests or clotting tests
- Pregnancy test
- Pelvic ultrasound to look for fibroids, polyps, or other structural issues
- Endometrial biopsy in some cases, especially when bleeding is persistent or you are older, to examine the lining
- Hysteroscopy, a thin camera used to look inside the uterus, if needed
Costs vary widely by country and insurance, so ask about pricing and coverage in advance if that is a concern.
Treatment options clinicians commonly discuss
Which option fits depends on the cause, your age, whether you want to become pregnant, and your preferences. A clinician decides, but it helps to know the general menu.
- Treatment for iron deficiency, if tests show it. Do not start iron on your own without asking, since a clinician may want to test first.
- Anti-inflammatory pain relievers taken during periods, which can reduce flow for some people. Ask a clinician or pharmacist whether they are safe for you, particularly if you take blood thinners or have stomach, kidney or bleeding problems.
- Tranexamic acid, a non-hormonal prescription medicine taken only during heavy bleeding
- Hormonal options, such as combined hormonal pills, progestin-only methods, or a hormonal intrauterine device, which can substantially reduce bleeding for many people
- Procedures: Endometrial ablation, removal of fibroids or polyps, and uterine artery embolization for some fibroids
- Hysterectomy, typically considered when other options have not worked and a person does not want future pregnancy
Hormonal treatments can also address hormone-linked symptoms discussed in what hormone changes can feel like day to day. Never start or stop prescription treatments without medical advice, and tell your clinician if you are trying to conceive.
Heavy periods and iron deficiency
Repeated blood loss can lower iron stores before it causes anemia. Early symptoms of low iron include fatigue, difficulty concentrating, restless legs, and hair shedding, which are easy to blame on stress or busy life. A ferritin test can detect low stores even when hemoglobin is normal. Iron-rich foods help, but they usually cannot make up for ongoing heavy loss, so treatment of the bleeding itself matters.
To keep notes between now and your visit, use the symptom and cycle diary and questions to bring to your clinician.
Where this comes from
The symptom list and the guidance on when to seek care follow the Mayo Clinic’s public information on heavy menstrual bleeding (menorrhagia), as summarized in published sources. The causes, tests and treatment options reflect commonly published patient information from gynecology and hematology bodies. Thresholds and treatments change over time, and local services and costs differ, so check current advice with your own clinician.