--- title: "Heavy periods: how much bleeding is too much?" description: "Signs of heavy periods, possible causes, anaemia symptoms, what a GP may check, and when fast bleeding or feeling faint needs help." url: "https://myruva.co/learn/heavy-periods-how-much-is-too-much" language: "en-GB" topic: "Symptoms" published: "2026-10-18" updated: "2026-10-18" author: "Ruva team" reading_minutes: 5 --- # Heavy periods: how much bleeding is too much? Signs of heavy periods, possible causes, anaemia symptoms, what a GP may check, and when fast bleeding or feeling faint needs help. *Written and reviewed by the Ruva team · Updated 2026-10-18 · Symptoms* If your periods soak through pads or tampons, leak onto bedding or make you plan your day around toilets, talk to a GP. You don't need to measure your bleeding in millilitres to ask for help. The NHS lists these [signs of heavy periods](https://www.nhs.uk/conditions/heavy-periods/): - You need to change a pad or tampon every 1 to 2 hours, or empty a cup more often than recommended. - You use two types of period product together to manage the bleeding. - You bleed for more than 7 days. - You pass clots bigger than about 2.5 cm, roughly the size of a UK 10p coin. - Blood floods through to your clothes or bedding, or you miss everyday activities because of bleeding. [ACOG's guidance on heavy menstrual bleeding](https://www.acog.org/womens-health/faqs/heavy-menstrual-bleeding) adds a few more signs. These include soaking a product every hour 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 example of every 1 to 2 hours. You can ask for help before your bleeding gets as heavy as either example. ## Fast bleeding or feeling faint: when to act urgently Get medical advice quickly if you're [soaking a pad or tampon every hour for 2 to 3 hours, or bleeding makes you weak or lightheaded](https://medlineplus.gov/ency/article/007496.htm). In the UK, contact an urgent GP service or NHS 111. Elsewhere, use your local urgent medical service. ACOG calls it an emergency if you [change a product every hour for more than two hours, with chest pain, shortness of breath and lightheadedness or dizziness](https://www.acog.org/womens-health/faqs/abnormal-uterine-bleeding). Get emergency care straight away. Severe or worsening pelvic pain also needs emergency help. So does pelvic pain with faintness, difficulty breathing or heavy vaginal bleeding. Follow the [NHS advice on pelvic pain](https://www.nhs.uk/symptoms/pelvic-pain/): in the UK, call 999 or go to A&E. Elsewhere, call your local emergency number or go to an 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](https://www.nhs.uk/conditions/iron-deficiency-anaemia/). Tell your GP if you have these symptoms as well as heavy bleeding. They can check you and arrange blood tests. Symptoms alone don't confirm anaemia. Describe what has changed, for example if you now get breathless doing something that used to feel easy. If you have iron deficiency anaemia, treatment can include iron tablets while the cause is dealt with. Heavy periods can also be treated with medicine. Ask about both parts of the plan: replacing the iron you've lost, and managing the bleeding that may be causing it. Follow the clinician's instructions for any iron treatment. ## What can make periods heavy? Heavy periods have several possible causes. A clinician may look at more than one. Sometimes [the cause stays unknown](https://www.acog.org/womens-health/faqs/heavy-menstrual-bleeding). Changes in the womb include fibroids and polyps. In adenomyosis, tissue from the womb lining grows into the muscle wall of the womb. It can cause heavy, painful periods. ACOG describes these [causes of abnormal bleeding](https://www.acog.org/womens-health/faqs/abnormal-uterine-bleeding). Changes in ovulation can also affect bleeding. When you don't ovulate regularly, the womb lining can get too thick in places. This is linked with puberty and perimenopause. It is also linked with conditions such as polycystic ovary syndrome and an underactive thyroid. A heavy period alone can't tell you if you have any of these. Bleeding disorders affect how your blood clots. Tell the GP if you've had heavy periods since your very first periods. Also mention frequent nosebleeds, bruising easily or bleeding after dental work. These can be [clues to a bleeding disorder](https://www.acog.org/womens-health/faqs/abnormal-uterine-bleeding). Medicines and contraception can play a part too, including [blood thinners, aspirin and the copper IUD](https://www.acog.org/womens-health/faqs/heavy-menstrual-bleeding). Bring the names of your medicines and your contraception method to the appointment. Talk to the clinician about any changes. Other causes include [pelvic infections and, less often, cancer](https://medlineplus.gov/ency/article/007496.htm). Problems in pregnancy can also cause bleeding that needs checking. Don't assume it is a period. Mention any [bleeding between periods](https://myruva.co/learn/spotting-between-periods) separately. ## Booking the appointment and describing the problem Book an appointment if heavy periods are affecting your life, have been going on for a while, or come with severe period pain. Also [see a GP for bleeding between periods or after sex](https://www.nhs.uk/conditions/heavy-periods/). The same goes for heavy periods with pain when peeing, pooing or having sex. Explain how it affects you, even if your periods have always been heavy. “I leave work to change my clothes” or “I avoid going out on the heaviest days” shows the GP the effect on your life. You don't need a full diary before you contact the surgery. If you keep a record, include [dates, flow and other symptoms](https://medlineplus.gov/ency/article/007496.htm). Note when bleeding starts and stops, how often pads or tampons get soaked, any leaks or clots, and how it affects your day. Keep changes you made for comfort apart from changes you needed because a product was full. To organise those details, use [irregular cycles: what to log and when to ask](https://myruva.co/learn/irregular-cycles-what-to-log-and-when-to-ask). For help describing pain on its own, see [period pain and when to seek help](https://myruva.co/learn/period-pain-whats-normal). ### Checks the GP may suggest Expect questions about the bleeding, your health history and your medicines. Your clinician may examine your tummy and pelvis. Tests can include [a full blood count and other tests chosen to match your symptoms](https://medlineplus.gov/ency/article/007496.htm). You may need a pregnancy test. Other checks can include an ultrasound scan or a hysteroscopy. A hysteroscopy uses a thin instrument to look inside the womb. Some people need a sample of the womb lining taken for testing. The tests you have will depend on your assessment. Ask what each test is looking for and how the result would change your treatment. A [full blood count helps check for anaemia](https://www.nhs.uk/conditions/iron-deficiency-anaemia/). So tell the GP about tiredness or breathlessness, not just the bleeding. ## Choosing treatment, including future pregnancy plans [Treatments for heavy periods](https://www.nhs.uk/conditions/heavy-periods/) include medicines such as tranexamic acid to reduce bleeding, and prescription anti-inflammatory painkillers. There are also hormonal options such as the combined pill or the hormonal coil (IUS). What suits you depends on your situation. Check how to take any medicine with the prescriber or pharmacist. Don't choose a dose from an article. If the first treatment doesn't help, or the GP suspects an underlying condition, they may refer you to a specialist. Procedures can include removing fibroids, treating the womb lining or removing the womb. These are options a specialist offers. Talk about any plans for future pregnancy before you agree to a procedure. [Pregnancy after endometrial ablation can be dangerous](https://www.acog.org/womens-health/faqs/heavy-menstrual-bleeding), so you still need contraception afterwards. A hysterectomy removes the womb, which means you can't carry a pregnancy. Ask what each option would mean for you, including if you're not sure about future pregnancy. ## Quick answers ### How heavy is too heavy for a period? Signs include changing a pad or tampon every 1 to 2 hours, bleeding through to clothes or bedding, clots bigger than about 2.5 cm, or bleeding for more than 7 days. These are the NHS signs of heavy periods. You can ask for help if bleeding affects your life, even if you don't have every sign. ### Can heavy periods make me tired? Heavy periods can cause iron deficiency anaemia. Possible symptoms include tiredness, low energy, breathlessness, palpitations and paler skin. Tell a GP. Don't assume tiredness is just part of your period. ### When does heavy period bleeding need urgent care? Get medical advice quickly if you soak through a pad or tampon every hour for 2 to 3 hours, or if bleeding makes you weak or lightheaded. Heavy bleeding with chest pain, breathlessness and dizziness needs emergency care. Severe pelvic pain, or pelvic pain with faintness, also needs emergency help. ## Sources 1. [Heavy periods](https://www.nhs.uk/conditions/heavy-periods/), NHS 2. [Heavy Menstrual Bleeding](https://www.acog.org/womens-health/faqs/heavy-menstrual-bleeding), American College of Obstetricians and Gynecologists 3. [Iron deficiency anaemia](https://www.nhs.uk/conditions/iron-deficiency-anaemia/), NHS 4. [Abnormal Uterine Bleeding](https://www.acog.org/womens-health/faqs/abnormal-uterine-bleeding), American College of Obstetricians and Gynecologists 5. [Vaginal or uterine bleeding](https://medlineplus.gov/ency/article/007496.htm), MedlinePlus 6. [Pelvic pain](https://www.nhs.uk/symptoms/pelvic-pain/), NHS --- This guide is general information to help you keep and use your own records. It isn’t medical advice. If you’re worried about a symptom, or something changes suddenly, talk to a doctor, nurse or pharmacist.