Heavy periods: how much bleeding is too much?

Periods that soak through products, leak onto bedding or make you plan the day around toilets are worth discussing with a GP. You don’t need a measurement in millilitres to ask for help.

The NHS lists these signs of heavy periods:

• Needing to change a pad or tampon every 1 to 2 hours, or emptying a cup more often than recommended.
• Using two types of period product together to manage the bleeding.
• Bleeding for more than 7 days.
• Passing clots larger than about 2.5 cm, roughly the size of a UK 10p coin.
• Flooding through to clothes or bedding, or missing everyday activities because of bleeding.

ACOG’s heavy menstrual bleeding guidance also describes hourly soaking for several hours, changing products during the night and clots at least the size of a US quarter. Its hourly example is more frequent than the NHS’s 1-to-2-hour example. You can seek help before bleeding reaches the heaviest flow described.

Fast bleeding or faintness: when to act urgently

Seek medical advice promptly if you’re soaking a pad or tampon every hour for 2 to 3 hours, or bleeding makes you weak or lightheaded. In the UK, contact an urgent GP service or NHS 111; elsewhere, use your local urgent medical service.

Hourly product changes for more than two hours with chest pain, shortness of breath and lightheadedness or dizziness are an emergency, according to ACOG. Seek emergency care immediately.

Severe or worsening pelvic pain, or pelvic pain with faintness, difficulty breathing or heavy vaginal bleeding, also needs emergency help. Follow the NHS pelvic pain advice: call 999 or go to A&E in the UK, or use your local emergency number or emergency department. Don’t drive yourself if you feel faint.

Tell the GP about tiredness too

Heavy periods are a common cause of iron deficiency anaemia. Symptoms include tiredness and low energy, shortness of breath, noticeable heartbeats, paler skin and headaches.

Tell your GP if you have these symptoms alongside heavy bleeding. They can assess you and arrange blood tests; symptoms alone don’t confirm anaemia. Describe what changed, such as becoming breathless during an activity that used to feel comfortable.

If iron deficiency anaemia is found, treatment can include iron tablets while its cause is addressed. Heavy periods can also be treated with medicine. Ask about both parts of the plan: replacing missing iron and managing the bleeding that may be contributing to it. Follow the clinician’s instructions for any iron treatment.

What can make periods heavy?

Heavy menstrual bleeding has several possible explanations. A clinician may consider more than one, and sometimes the cause remains unknown.

Changes in the womb include fibroids and polyps. Adenomyosis involves tissue from the womb lining growing into its muscle wall and can cause heavy, painful periods. ACOG describes these causes of abnormal bleeding.

Changes in ovulation can also affect bleeding. When ovulation isn’t regular, the womb lining can become too thick in places. This pattern is linked with puberty and perimenopause, and with conditions including polycystic ovary syndrome and an underactive thyroid. A heavy period alone cannot identify any of these conditions.

Bleeding disorders affect how blood clots. Tell the GP about heavy periods dating back to your earliest periods, frequent nosebleeds, easy bruising or bleeding after dental work. These can be clues to a bleeding disorder.

Medicines and contraception may contribute too, including blood thinners, aspirin and the copper IUD. Bring your medication names and contraceptive method to the appointment, and discuss any changes with the clinician.

Other causes include pelvic infections and, less commonly, cancer. Pregnancy complications can also cause bleeding that needs assessment; don’t assume it is a period. Mention bleeding between periods separately.

Booking the appointment and describing the problem

Book an appointment if heavy periods are affecting your life, have been happening for some time, or come with severe period pain. See a GP for bleeding between periods or after sex too, and for heavy periods with pain when peeing, pooing or having sex.

Explain the effect even if you have always had heavy bleeding. “I leave work to change my clothes” or “I avoid going out on the heaviest days” tells the GP how it affects you. You don’t need a complete diary before contacting the surgery.

If you keep a record, include dates, flow and other symptoms. Note when bleeding starts and ends, how often products are soaked, any leaks or clots, and the effect on your day. Separate changes made for comfort from changes needed because a product was full.

Use irregular cycles: what to log and when to ask to organise those details. For help describing pain separately, see period pain and when to seek help.

Checks the GP may suggest

Expect questions about the bleeding, your health history and medicines. Your clinician may examine your tummy and pelvis. Tests can include a full blood count and other investigations chosen according to your symptoms. A pregnancy test may be needed.

Further checks can include an ultrasound scan or hysteroscopy, a procedure using a thin instrument to look inside the womb. Some people need a sample of the womb lining for testing. Which tests you have will depend on your assessment. Ask what a proposed test is looking for and how the result would affect treatment.

A full blood count helps assess anaemia, so tell the GP about fatigue or breathlessness as well as the bleeding.

Choosing treatment, including future pregnancy plans

Treatments for heavy periods include medicines such as tranexamic acid to reduce bleeding, prescription anti-inflammatory painkillers, and hormonal options such as the combined pill or hormonal coil (IUS). Suitability depends on your circumstances. Check medicine instructions with the prescriber or pharmacist; don’t choose a dose from an article.

If initial treatment doesn’t help, or an underlying condition is suspected, a GP may refer you to a specialist. Procedures can include removing fibroids, treating the womb lining or removing the womb. These are specialist options.

Discuss future pregnancy plans before agreeing to a procedure. Pregnancy after endometrial ablation can be dangerous, so contraception is still needed afterwards; hysterectomy removes the womb and means you cannot carry a pregnancy. Ask what each option would mean for you, including if you’re unsure about future pregnancy.