Heavy Menstrual Flow (Menorrhagia)

How heavy is too heavy?

A typical period lasts 4 to 7 days with total blood loss of roughly 30 to 40 ml (2 to 3 tablespoons). Heavy menstrual bleeding is formally more than 80 ml per cycle, but nobody measures that at home. Doctors now define it by its effect on your life. Signs your flow is heavy:

• soaking through a pad or tampon every 1 to 2 hours for several hours in a row
• needing to use a pad and tampon together, or extra-large protection
• changing protection during the night, or bleeding through onto bedding
• passing clots the size of a quarter or larger
• bleeding for more than 7 days
• restricting work, exercise or social life during your period
• symptoms of anemia: tiredness, breathlessness, pale skin, cravings for ice

A menstrual cup measures volume directly: most cups hold 25 to 30 ml, so filling one several times a day suggests heavy flow.

Causes of heavy menstrual flow

Doctors use the PALM-COEIN system. PALM covers structural causes; COEIN covers non-structural ones.

Teenagers

Heavy periods from the first period are a reason to test for a bleeding disorder. Up to 1 in 5 teens with heavy periods has one, most often von Willebrand disease. Irregular, heavy bleeding is also common in the first years of periods because ovulation is not yet regular.

Perimenopause

In the years before menopause, skipped ovulation lets the lining build up and then shed heavily. Any bleeding after menopause, and heavy irregular bleeding after 45, needs assessment to rule out endometrial cancer.

Heavy period with clots

Small clots are normal on heavy days. The body uses anticoagulant chemicals to keep menstrual blood liquid, and when flow is fast these are overwhelmed. Clots larger than a quarter, or frequent clots, suggest heavy bleeding and are worth checking, especially with fibroids or adenomyosis.

Complications

• Iron deficiency anemia: heavy periods are the most common cause in women of reproductive age. Symptoms include fatigue, breathlessness, headaches, hair shedding, restless legs and poor concentration.
• Reduced quality of life: missed school or work and avoided activities.
• Sudden heavy loss needing emergency treatment.

How doctors find the cause

A doctor will ask about cycle length, days of bleeding, how often you change protection, clots, pain, bleeding between periods or after sex, bleeding elsewhere in the body, medicines, contraception, and family history.

Common tests:

• Complete blood count and ferritin for anemia and iron stores
• Pregnancy test
• Thyroid function if symptoms suggest it
• Bleeding disorder tests (von Willebrand panel and others) if heavy since the first period or with other bleeding symptoms
• Pelvic ultrasound (often transvaginal) for fibroids, polyps and adenomyosis
• Endometrial biopsy for women over 45, or younger with risk factors such as obesity or PCOS, or bleeding that persists despite treatment
• Hysteroscopy: a camera into the uterus to see and remove polyps or small fibroids

Treatment

Medicines

• Levonorgestrel IUD (hormonal coil): the most effective medical treatment, reducing blood loss by over 80% in most users after a few months. Also contraceptive.
• Tranexamic acid: a non-hormonal tablet taken only on heavy days, reducing flow by about a third to a half. Not for people with a history of blood clots.
• NSAIDs such as ibuprofen or naproxen during the period reduce flow by about 20 to 40% and ease cramps. Follow the label dose, and avoid with stomach ulcers, kidney disease or bleeding disorders.
• Combined hormonal contraception or progestin tablets, injections or implants.
• GnRH-based medicines for fibroid-related bleeding.
• Iron supplements to treat anemia. Take with vitamin C and away from tea and calcium for better absorption.

Procedures

• Hysteroscopic removal of polyps or fibroids inside the cavity
• Endometrial ablation: destroys the uterine lining to reduce bleeding, only for people who do not want future pregnancy
• Uterine artery embolization or myomectomy for fibroids
• Hysterectomy: a definitive option when other treatments fail

Frequently asked questions

How do I know if my period is too heavy?

Your period is likely heavy if you soak a pad or tampon every 1 to 2 hours, pass clots larger than a quarter, need to change protection at night, bleed more than 7 days, or feel tired and breathless. If it limits your daily life, it is worth discussing with a doctor.

What causes heavy periods all of a sudden?

A sudden change can be caused by pregnancy complications, a new fibroid or polyp, starting a copper IUD or blood thinner, thyroid problems, or hormonal changes around perimenopause. Bleeding heavy enough to soak a pad an hour needs urgent care.

Are heavy periods with clots normal?

Small clots on the heaviest days are common. Frequent clots larger than a quarter suggest heavy menstrual bleeding and should be checked, as they are often linked to fibroids, adenomyosis or a bleeding disorder.

Can heavy periods cause anemia?

Yes. Heavy periods are the most common cause of iron deficiency anemia in women of reproductive age. Tiredness, breathlessness, pale skin, hair shedding and craving ice are typical signs. A blood count and ferritin test can confirm it.

What is the best treatment for heavy periods?

The hormonal (levonorgestrel) IUD is the most effective medical treatment for most people. Tranexamic acid and NSAIDs taken during the period are non-hormonal options. The best choice depends on the cause, whether you want contraception or a future pregnancy, and your preferences.