Abnormal uterine bleeding

7 min read

What is abnormal uterine bleeding?

Abnormal uterine bleeding (AUB) describes any abnormal bleeding from the womb (uterus) that is a change from a woman’s normal menstrual cycle. This change may involve how often you get your period, how much blood you lose, and/or how long it lasts. You may also notice bleeding between your periods.

AUB is a common condition that affects up to one in three women of childbearing age.

If you are experiencing any uterine bleeding that is a change from your normal menstrual cycle, it is important to see your doctor. Even if your doctor cannot find a specific medical cause of the bleeding, treatments, such as anti-inflammatory medicines and hormone therapy, are available.

Abnormal uterine bleeding symptoms

AUB affects every woman differently. For some women, AUB can be an ongoing problem that continues for months. For others, it can be a single, sudden episode of bleeding that may require immediate medical attention to stop the blood loss.

AUB symptoms may include:

  • heavy periods
    - the bleeding is so heavy that it may interfere with your work, social life, and your physical and emotional wellbeing
  • irregular periods
    – your periods may be more or less frequent than normal or arrive at random times, with no pattern to them
  • no periods at all (for 3 months or longer)
  • periods that are longer (more than 8 days) or shorter (less than 3 days) than average
  • irregular bleeding between your periods
  • bleeding after sex
  • bleeding just before your period starts or just after it finishes
  • bleeding after you have gone through the menopause
  • bleeding before the age of 9 years

Abnormal uterine bleeding causes

AUB can be caused by many things. Causes of AUB include:

  • a problem with the hormones that control the release of an egg from your ovaries (ovulation)
  • physical abnormalities in your uterus or cervix such as
    , polyps (small tissue overgrowths) or adenomyosis (when small pieces of womb lining are found in the womb’s muscle layer)
  • bleeding or blood clotting problems caused by certain medical conditions or blood-thinning medicines
  • cancer or pre-cancer of the cervix or uterus
  • certain treatments or medication, such as hormones used in contraceptives or
    hormone replacement therapy
  • infections or inflammation of the cervix or womb lining
  • medical conditions, such as an
    underactive thyroid (hypothyroidism)
    liver disease
  • genetic conditions, such as Turner’s disease

Abnormal uterine bleeding diagnosis

Your doctor will ask about your symptoms and their impact on your daily life and general health, and ask about your medical history, sexual history, any past pregnancies, family medical history, medication, and other factors before making a diagnosis of AUB.

Your doctor is also likely to examine you by:

  • feeling your abdomen
  • feeling and looking at the inside of your vagina (using an instrument called a speculum)

You may be given the option to see a female doctor if this makes you feel more comfortable.

The tests usually performed to check for other causes include:

  • a pregnancy test – to rule out pregnancy as the cause of bleeding if you are sexually active (even if you are using contraception)
  • blood tests – to check for anaemia following blood loss, blood clotting abnormalities, and/or to measure your hormone levels
  • imaging of the womb – this can include an ultrasound scan or sonohysterography (an ultrasound scan during which a small amount of sterile salt water is introduced into your uterus)
  • hysteroscopy – a camera test to look at the inside of your uterus

Abnormal uterine bleeding treatment

While unexplained bleeding can be distressing, treatment can stop the bleeding for most women.

A variety of strategies are used for AUB management. These focus on controlling the bleeding, returning your periods back to normal, and treating or preventing complications, such as anaemia.

If you are diagnosed with AUB, your treatment will depend on various factors, including:

  • your age
  • how heavy your bleeding is
  • if a cause of the bleeding has been identified
  • whether imaging scans show that you have a thickened womb lining
  • whether you plan to have a baby in the future

When the exact cause of the bleeding is known, your treatment will aim to correct the specific cause. For example:

  • antibiotics may be used to treat a
    womb infection
  • surgery,
    , or
    may be used to treat
    , endometrial, or
    uterine cancer
  • fibroids
    , polyps, and adenomyosis may require hormone therapy, surgery, or no treatment at all
  • blood clotting abnormalities caused by medication may require a change in medication type or dose, while inherited blood clotting disorders may be helped by medications that help the blood to clot
  • your doctor may adjust the dose, type, or timing of any medication or treatment that may be causing your bleeding

If your doctor is unable to identify a specific medical condition as the cause of your bleeding, five types of treatment can be used to manage the bleeding. These are:

Hormones (progestogens and oestrogens)

Hormones, such as progestogens and oestrogens, can help to correct any reproductive hormone imbalance which may be contributing to your symptoms. These hormones can keep the menstrual cycle regular, and treat excessive menstrual bleeding.

The combined oral contraceptive pill is often used. Progesterone can help reduce heavy bleeding in women who do not ovulate regularly. It is available in different forms, such as oral tablets, implants, injection, or a

progesterone-containing intrauterine system (IUS)

Anti-inflammatory medication

For some women, hormone therapy is not suitable. In this case, anti-inflammatory medications called non-steroidal anti-inflammatory drugs (NSAIDs) are used.

Examples of this medication include ibuprofen, mefenamic acid, and naproxen. These help to manage AUB symptoms by reducing the body's production of a hormone-like substance called prostaglandin.

Medication to reduce blood loss

Tranexamic acid may be prescribed by your doctor. It can slow the rate of blood loss by encouraging the blood in the uterus to clot.


If your bleeding is not responding to treatment, your doctor may recommend surgery.

If you do not plan to have children, an endometrial ablation (using heat or laser to remove part of the womb lining) or total removal of the uterus may be recommended.

If the bleeding is due to fibroids or polyps, these growths can be removed during a keyhole procedure called a


If your doctor considers your bleeding to be very heavy, you will need to be admitted to hospital for emergency treatment. Emergency care may involve fluids (given into your veins via a drip), medication, and, in serious cases, surgery as a last resort.

Period suppression medication

If you cannot have hormone treatment, surgery, or anti-inflammatory medication as part of your AUB treatment, your doctor may recommend a type of medication that suppresses your periods, called gonadotropin-releasing hormone (GnRH) analogues.


AUB is a common condition which affects up to one in three women of childbearing age. It can be a distressing condition that has a big impact on your physical, social, and emotional quality of life.

If you are concerned that you may have AUB, you should see a doctor as soon as possible.

To find answers to any other health questions you might have, visit our

Health A-Z

Complications of abnormal uterine bleeding

The risk of AUB complications depends on how long you’ve been bleeding and how severe the blood loss is.

The most common complications of AUB are:


Excessive or long-term blood loss can lead to

iron deficiency anaemia
in some women with AUB. This can be diagnosed easily by a blood test, and treated with iron tablets or iron given through a vein or into the muscle. More serious cases of anaemia may require a blood transfusion.

Abnormal womb lining growth

If AUB is left untreated for many years, the womb lining is at increased risk of abnormal growth. This can lead to a condition called endometrial hyperplasia (when the womb lining becomes abnormally thicker) which carries an increased risk of developing

endometrial cancer

Important: Our website provides useful information but is not a substitute for medical advice. You should always seek the advice of your doctor when making decisions about your health.