When should you go to the hospital for heavy menstrual bleeding?

Katherine Maslowski

Do you have heavy periods/heavy menstrual bleeding? Or have you ever wondered if your periods are heavy but been too shy to ask? Today we are going to talk about what is normal, what is heavy and when you should seek help.


How much blood do you lose on your period? What is considered normal?

You probably have a pretty good idea of what your period is like and what is “normal” for you. No one knows your body better than you do. But you might never have discussed your periods with friends or family. You might be wondering if your periods would be considered “heavy menstrual bleeding”. The medical term for heavy menstrual bleeding is menorrhagia. Approximately 1 in 20 people with periods have menorrhagia.

Normal menstrual bleeding

The “average” woman loses less than 80mL of blood with each period and bleeds for 4-7 days.

It is important to remember that everyone is different. “Average” is just what we have found by looking at lots of different women’s periods.

Heavy menstrual bleeding

Anything over 80mL of blood loss in a single period is considered “heavy menstrual bleeding”. Obviously, nobody actually measures how much they are bleeding (although menstrual cups do make this easier these days) so in reality this is just a rough estimate. A more realistic way to think about the amount of blood is if you have to change your pad/tampon every 1-2 hours. Passing clots bigger than a 10p coin would also be considered heavy. Bleeding through your clothes or onto your sheets at night would also indicate that you have heavy menstrual bleeding.

Heavy periods can also relate to the duration of your periods. If you bleed for more than seven days in a row then this also counts as heavy menstrual bleeding.

Everyone is different. Some people might have heavy periods that last only a few days, some bleed very lightly for longer. The NHS website has a quiz to help you work out if your periods are heavy, if you are not sure.

There are always going to be people who don’t fit the description of “average”, but they are completely fine. Everyone’s cycle is different and the effect that heavy menstrual bleeding has on your life will depend on a lot of factors. Your period is only a “problem” if it is interfering with your life or stopping you from doing things you want to do. Heavy bleeding can stop you from leaving the house, or prevent you from going to work.

This being said, heavy menstrual bleeding can have important implications for your general health. So it is important to know what is normal for you, and what you should see a doctor about.


When to seek medical attention: Effects and complications of heavy menstrual bleeding

When to go to the hospital urgently

Periods are “normal”. Most people who have a uterus will have periods (unless they are actively stopping them). This can lead society to teach us that periods are something we just have to deal with. This can be a dangerous mindset.

I have met a lot of women in my job who have had very heavy periods who have just thought that it was normal. Or they didn’t want to complain. Or they had too many other things to deal with and didn’t have time to ask for help.

This bit is important

Consistently heavy menstrual bleeding can be dangerous. If you are bleeding and you are having to change a pad or tampon (because it is full, not just because you want to) more than once an hour for two consecutive hours you need to see a doctor urgently (call an ambulance/go to the emergency department).

This applies to any sort of vaginal bleeding of any cause. Whether it is your period, you are having a miscarriage, you are bleeding for no apparent reason or you have some sort of illness that causes you to bleed. Don’t wait at home for it to stop. No one at a hospital will tell you off for asking for help if you are bleeding like that. Even if it stops without anyone doing anything.

Also, if you feel like you might pass out (dizzy/lightheaded) or you have pain in your chest or difficulty breathing then see a doctor or go to the emergency department urgently.

Now that we are clear on when you need to ask for help now, we can talk about the less urgent (but still important) complications of heavy menstrual bleeding.

Complications of heavy menstrual bleeding


Heavy menstrual bleeding can lead to anaemia. This is when you are regularly losing too much blood for your body to replace the red blood cells (the ones that carry oxygen around your body) fast enough. This sounds very scary (and it can be, as we talked about above) but usually your body copes with this.

You might feel tired and run down, like you don’t have enough energy or feel lightheaded/dizzy when you stand up. These are all signs that your blood cells are struggling to carry enough oxygen around your body.

Anaemia can be treated but it is important to talk to your doctor and get a blood test if you are having any of these symptoms. Severe anaemia can also cause shortness of breath or chest pain. If you are experiencing this please see a doctor urgently.

Heavy menstrual bleeding can also be a sign of an underlying condition. Check out this article if you want to know more about what can cause heavy periods. It is always a good idea to talk to your doctor if you are worried about your menstrual bleeding.

Disrupted sleep

Heavy menstrual bleeding can disrupt your sleep. It can often mean you wake at night to change your pad/tampon or even just because you are worried about your bleeding. Not getting enough sleep can then affect your energy and your mood.


Sometimes people with heavy periods can also experience period pain. This can make the experience of your periods even worse than just the heavy bleeding alone.


Treatment options for heavy menstrual bleeding


When we bleed we lose iron. Iron is important for making red blood cells, so we need to make sure we have enough. Red meat is the most well-known source of iron but things like leafy green veges (e.g. spinach) also have iron.

If you don’t eat meat or you struggle to include enough iron in your diet then it may be worth talking to your doctor about iron supplements.

Medical Treatments and Surgery

There are a lot of different options for treating heavy menstrual bleeding. This article outlines the basic options available.

It is always important to speak to your doctor though, as some treatments are only appropriate in specific situations.


Hopefully, this has helped you to see what is medically considered “normal”, what’s not normal and what you should seek help for. You don’t have to put up with heavy bleeding that is affecting your life!


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Posted By  : Katherine Maslowski

Katherine Maslowski

Katherine Maslowski

Katherine is a junior doctor from New Zealand who has experience working in Obstetrics and Gynaecology and is currently studying an MSc in Women’s Health. She is passionate about women’s health and empowering women to learn about their bodies and understand how they work. She is particularly interested in sexual and reproductive health and helping women to make educated, informed choices about their health and wellbeing.