Heavy periods are common, but they can have a big effect on a woman’s everyday life. Heavy periods aren’t necessarily a sign there is anything wrong, but they can affect you physically and emotionally. Excessive menstrual bleeding is usually known as menorrhagia. It can be a distressing problem and one of the most common reasons for women to visit their GP. 1 in 20 women consult their GP every year about this problem.

In this article, we will dive into the most common reasons for heavy bleeding, the symptoms and how to avoid and treat the problem.

What’s on this page:

What causes heavy periods?

In some cases, the cause of heavy menstrual bleeding is unknown, but a number of conditions may cause menorrhagia. Common causes include:

Hormone imbalance. In a normal menstrual cycle, a balance between the hormones estrogen and progesterone regulates the buildup of the lining of the uterus (endometrium), which is shed during menstruation. If a hormone imbalance occurs, the endometrium develops in excess and eventually sheds by way of heavy menstrual bleeding.

Or in some cases, dysfunction of the ovaries might be the cause. If your ovaries don’t release an egg (ovulate) during a menstrual cycle (anovulation), your body doesn’t produce the hormone progesterone, as it would during a normal menstrual cycle. This leads to hormone imbalance and may result in menorrhagia.

Cancer. Uterine cancer and cervical cancer can cause excessive menstrual bleeding, especially if you are postmenopausal or have had an abnormal Pap test in the past.

Inherited bleeding disorders are also a possibility. Some bleeding disorders, such as von Willebrand’s disease, a condition in which an important blood-clotting factor is deficient or impaired, and can cause abnormal menstrual bleeding.

Intrauterine device (IUD). Menorrhagia is a well-known side effect of using a non-hormonal intrauterine device for birth control. Your doctor will help you plan for alternative management options.

Medications. Certain medications, including anti-inflammatory medications, hormonal medications such as estrogen and progestins, and anticoagulants such as warfarin (Coumadin, Jantoven) or enoxaparin (Lovenox), can contribute to heavy or prolonged menstrual bleeding.

Other medical conditions. A number of other medical conditions, including liver or kidney disease, may be associated with menorrhagia.

It’s difficult to define exactly what a heavy period is because it varies from woman to woman. Heavy for one woman may be normal for another. Most women will lose less than 16 teaspoons of blood (80ml) during their period, with the average being around 6 to 8 teaspoons. Heavy menstrual bleeding is defined as losing 80ml or more with each period, having periods that last longer than 7 days, or both.


Bleeding is considered abnormal when more than 80ml is lost, since above this point there is a risk of anaemia. Some women lose much more blood. Bleeding more than a litre each month has been recorded, but this is very unusual.

Regular heavy periods with no other bleeding during the cycle are not normally associated with significant disease in young women. Irregular heavy periods and bleeding between periods or after sexual intercourse may indicate a serious condition. Other symptoms to watch out for include prolonged periods, tiredness, lightheadedness, poor sleep patterns and breathlessness.1

Symptoms to look for:

  • Are your periods heavier than usual? Do they last longer?
  • Does your bleeding soak through a pad or tampon every hour for two or more hours back to back?
  • Do you notice sudden gushes in your flow? Are there large blood clots?
  • Do you need to wake up to change your pads at night?
  • Are you bleeding for a week or longer?
  • Do you restrict what you do in your daily life because of your very heavy periods?
  • Are you feeling symptoms of anaemia (fatigue or shortness of breath)?

When should I see a doctor?

Some women will put off getting help because they’re not sure what’s considered to be heavy. Others will avoid seeking treatment because they mistakenly worry that a hysterectomy is the only option. There isn’t always an underlying problem, but to make sure, to see your doctor is always a good idea. Contact your GP if:

  • you’re worried about your bleeding
  • your periods have got heavier
  • you’re also having other symptoms, such as period pain or bleeding between your periods

Various treatments are available for heavy periods, including:

  • some types of contraception, like an intrauterine system (IUS) or the combined pill
  • medicines, like tranexamic acid
  • Surgery

How can I stop my heavy bleeding?

There are various treatments when it comes to heavy periods, depending on which one is more suitable for you and the condition. Medical treatment includes drugs which act either by reducing levels of prostaglandins or by affecting the blood clotting process that takes place in the womb during periods. A commonly prescribed drug is primolut-n, provera or utovlan.

Before choosing the treatment, it’s always advised to make an appointment with your GP, not only to see if your suitable for these treatments, but also if they are the right ones for you. To do this you might have to go through an exam to make sure there’s no underlying problem, that might need a different treatment.

Not all the treatments may be suitable for you. What treatment options you are offered will depend on:

  • your symptoms
  • your general health
  • the underlying cause of your heavy periods, if there is one
  • whether you’re trying for a baby or want to get pregnant in the future
  • your personal preferences

You should discuss benefits and risks of the different options with your doctor, including any impact on future fertility from some treatments.

How to diagnose heavy periods?

To try to find out what’s causing your heavy periods, your GP will ask about:
your medical history:

  • what your bleeding is like – for example, how long your periods normally last and how often you need to change sanitary products
  • any related symptoms you have, like period pain or bleeding between periods
  • what effect your bleeding is having on your everyday life

In cases of abnormal bleeding, it is important to discover if there is an underlying problem in the pelvis. This is done by means of a simple pelvic examination. The doctor inspects the vulva, vagina and cervix (neck of the womb) to make sure there is no abnormality that could account for the bleeding.

Sometimes further tests are needed.


  1. Online test – NHS