Most cases of period pain are a normal part of your menstrual cycle and can usually be treated at home.

The period pain occurs when the muscular wall of the womb contracts. Very mild contractions continually pass through your womb, but they are usually so mild that most women cannot feel them. During your period, the wall of your womb starts to contract more vigorously, to encourage the lining of your womb to shed away as part of your monthly menstrual cycle.

When the muscular wall of your womb contracts, it compresses the blood vessels that line your womb. This temporarily cuts off the blood supply (and hence oxygen supply) to your womb. Without oxygen, the tissues in your womb release chemicals that trigger pain in your body.

While your body is releasing these pain-triggering chemicals, it is also producing another set of chemicals known as prostaglandins. Prostaglandins encourage the womb muscles to contract further, therefore increasing the level of pain.

It is not yet known why some women experience more period pain than others. It has been suggested that some women may develop a build-up of prostaglandins, which means their contractions are much stronger than other women’s.

Period pain caused by a medical condition

Less commonly, your period pain may be caused by an underlying medical condition such as:

• Endometriosis: the cells that normally line the womb start to grow in other places within the body, usually in the fallopian tubes and ovaries. When these cells shed and fall away, they can cause intense pain. Read more about endometriosis.
• Fibroids: this condition occurs when non-cancerous tumours grow in the womb. They can make your periods heavy and painful. Read more about fibroids.
• Pelvic inflammatory disease: your womb, fallopian tubes and ovaries become infected with bacteria, leaving them severely inflamed (swollen and irritated). Read more about pelvic inflammatory disease.
• Adenomyosis: the tissue that normally lines the womb starts to grow within the muscular wall of the womb. This extra tissue can make your periods particularly painful.
• Intrauterine device (IUD): this is a form of contraception made from copper and plastic, which fits inside the womb. It can sometimes cause period pain, especially in the first few months after it is inserted.

If you have painful periods caused by an underlying condition, you may also have other symptoms, such as:

• irregular periods 
• bleeding in between periods
• thick or foul-smelling vaginal discharge
• pain during sex

You are more likely to develop this sort of period pain as you get older. Most affected women are aged 30-45.

Period pain caused by one of the above conditions is normally indicated by a change in your normal pattern of pain. For example, you may find your period pain has significantly increased, or that it lasts for much longer than normal.

If you experience a significant change to your normal period pattern, see your GP to discuss your symptoms.

Most women who have period pain find it is mild enough to treat at home. However, if your periods are causing you severe pain, contact your GP for advice.

Also contact your GP if you have:

• a fever
• sudden and severe pain in your abdomen
• a large amount of blood clots in your period
• thick or foul-smelling vaginal discharge

When you visit your GP they will look at your medical history and ask you to describe your symptoms. They may also ask about your menstrual cycle and sexual activity.

Try not to feel embarrassed or awkward when talking to your GP about this. They need to know this information to help them determine the cause of your period pain. It will allow them to provide the most appropriate treatment for your pain.

Pelvic examination

Although most cases of period pain are not caused by an underlying condition, your GP may feel it necessary to carry out a physical examination so that any other conditions can be detected or ruled out. Usually, the physical examination will involve your GP examining your pelvic area.

During a pelvic examination, your GP will examine your vulva and labia (external genitals) for signs of bleeding or infection. They may also need to examine you internally. This will involve your GP inserting gloved, lubricated fingers into your vagina to feel for any abnormalities in your womb or ovaries.

A pelvic examination will only be carried out by a health professional who is qualified to perform the procedure, such as a GP or a gynaecologist (a specialist in the female reproductive system). This type of examination will not be carried out without your consent, and you will have the option of having someone with you during the procedure.

Referral

If your period pain does not respond to treatment, or your GP suspects an underlying condition, you may be referred to a specialist. In most cases, you will be referred to a gynaecologist.

To determine what might be causing your period pain, your gynaecologist may have to carry out a series of tests and procedures. Some of these are included below.

• Pelvic ultrasound: an ultrasound scan uses high-frequency sound waves to produce an image of the inside of your body. It is a painless procedure, and will allow your specialist to detect any abnormalities in your reproductive organs.
• Laparoscopy: during this procedure, a small cut is made in your abdomen through which a fibro-optic telescope (laparoscope) is inserted. It can be used to look at your internal organs, as well as take samples of tissue. This procedure is normally carried out under general anaesthetic. Read more about laparoscopy.
• Hysteroscopy: this test allows your specialist to look inside your womb using a fibro-optic telescope, which is carefully passed through your vagina and into the womb to look for any abnormalities. Read more about hysteroscopy.
  

Most women experience some form of period pain during their lifetime. The medical term for period pain is dysmenorrhoea.

Period pain is usually felt as painful muscle cramps in your lower tummy, which can sometimes spread to your back and thighs. Sometimes the pain comes in intense spasms, while at other times the pain may be dull but more constant.

The pain usually starts when your bleeding begins, and normally lasts for 12-24 hours.

Read more about the symptoms of painful periods.

Why it happens

Most cases of period pain occur when the muscular wall of the womb contracts. This compresses the blood vessels that line your womb, which temporarily cuts off the blood supply (and hence oxygen supply) to your womb. Without oxygen, the tissues in your womb release chemicals that trigger pain in your body.

Occasionally, period pain can be caused by an underlying medical condition such as endometriosis or pelvic inflammatory disease (see box, right).

Read more about the causes of painful periods.

How common is it?

Period pain is very common. Some studies suggest that approximately three quarters of young women and a quarter to a half of adult women experience pain and discomfort during their period. For up to one in five women, this pain is so severe that it stops them from doing their daily activities.

What to do

Most cases of period pain can be treated at home. You can buy a number of painkillers over the counter to help manage your pain.

Find out how you can manage period pain at home.

If your period pain is severe, visit your GP to check that no medical condition is causing your pain.

Read about the diagnosis of period pain caused by an underlying medical condition.

The Map of Medicine is used by doctors throughout the NHS to determine the best treatment options for their patients. NHS Choices offers everyone in England exclusive and free access to this cutting-edge internet resource, which lets you see exactly what your doctor sees.

The information in the Map has been approved by the UK’s leading clinical experts, is based on the best available clinical evidence, and is continually updated. To take advantage of this unique resource go to:

Map of Medicine: dysmenorrhoea

Period pain is usually felt as painful muscle cramps in your lower abdomen (tummy).

Sometimes the pain comes in intense spasms, while at other times the pain may be dull but more constant.

Period pain can sometimes spread to your lower back and your thighs. You may also notice that the pain varies with each period. Some periods may cause you little or no discomfort, while others may be far more painful.

As well as feeling pain in your abdomen, you may have a number of other symptoms, such as:

• headaches
• nausea (feeling sick)
• tiredness
• feeling faint
• dizziness
• diarrhoea

How long will my period pain last?

Your period pain usually starts when your bleeding begins, although some women also feel pain several days before their period starts.

Period pain normally lasts for 12-24 hours, although in more severe cases it may last for several days. The pain is usually at its worst when your bleeding is heaviest.

The symptoms of painful periods tend to improve as you get older. Many women also notice an improvement after they have had children.

Most cases of period pain can be treated at home. You can buy a number of painkillers over the counter to help manage your pain.

There are also several self-help techniques that you can try.

Medication

Non-steroidal anti-inflammatory drugs (NSAIDs)

In most cases of period pain, your GP will either prescribe or advise you to take a non-steroidal anti-inflammatory drug (NSAID). This type of medicine works for approximately 7 in 10 women with period pain.

You can buy some NSAIDs over the counter, such as ibuprofen and aspirin. If these NSAIDs are not effective, your GP may prescribe you an alternative NSAID, such as naproxen or mefenamic acid.

NSAIDs are not suitable for people with asthma, or those with stomach, kidney or liver problems. Pregnant or breastfeeding women should also avoid taking them. Aspirin should not be given to anyone under 16 years of age. If you are not sure if NSAIDs are suitable, speak to your GP or pharmacist.

Other painkilling medicines

If NSAIDs are not suitable for you or you do not find them effective, you may be able to take an alternative painkilling medicine. Paracetamol has very few side effects and is easily available over the counter. However, studies have shown that it does not reduce pain as effectively as an NSAID.

If you are not getting enough pain relief from NSAIDs or paracetamol alone, your GP may prescribe you a painkiller called codeine to take as well.

Combined oral contraceptive pill

If you need a contraceptive as well as relief from period pain, your GP may prescribe you a combined oral contraceptive pill.

Combined contraceptive pills can help to ease period pain because they thin the lining of the womb and help to reduce the amount of prostaglandin chemicals that your body releases. If the lining of the womb is thinner, the muscles do not have to contract as much when it needs to shed away as part of your monthly menstrual cycle. Your period will also be lighter.

If you are not able to take the combined contraceptive pill for whatever reason, contraceptive implants or injections are good alternatives.

Self-help

There are a number of ways you can treat your painful periods at home. Although you may not stop your pain completely, these measures can often help to ease or reduce it.

• Exercise: although you may not want to exercise while you are having a painful period, keeping active can help to reduce pain. Try some gentle swimming, walking or cycling.
• Heat: applying heat to your tummy can help to ease your pain. You could try using either a heat pad or a hot water bottle. If using a hot water bottle, make sure the water is hot, not boiling, as you may damage your skin.
• Warm bath or shower: taking a bath or shower can help to relieve your pain, while also helping you to relax.
• Massage: light circular massage around your lower abdomen may help to reduce pain.
• Relaxation techniques: you might want to try a relaxing activity, such as yoga or Pilates, to help distract you from feelings of pain and discomfort.
• Transcutaneous electronic nerve stimulation (TENS): a TENS machine works by releasing small electrical impulses that stimulate the nerves in your pelvic area, helping to block pain. The impulses are released through sticky pads (electrodes) that are placed on your skin. TENS machines are widely available from pharmacies and can be used at home. Read more about TENS.

Period pain caused by a medical condition

If you have not managed to control your pain after three months of treatment with NSAIDs and/or the combined contraceptive pill, your GP may refer you to see a specialist for further investigations to rule out an underlying medical condition.

If your period pain is caused by an underlying condition, your treatment will depend on which condition you have. For example, pelvic inflammatory disease (PID) may require antibiotics to treat the infection, while fibroids may need to be surgically removed.

Read about the treatment of PID and the treatment of fibroids.

Although you may be prescribed painkillers to take in the meantime, it is important to treat your underlying condition.