Most women experience some form of period pain during their lifetime. The medical term for period pain is dysmenorrhoea. The pain caused by menstruation is usually felt in your lower abdominal area, but can also spread to your back and thighs.

How common is it?

Although it is not known exactly how many women experience period pain, research has shown that it is a very common condition. 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.  Most cases of period pain are a normal part of your menstrual cycle and can be treated at home. However, in some cases, period pain can be caused by an underlying medical condition such as endometriosis or pelvic inflammatory disease.  If your period pain is severe, visit your GP to check that no medical condition is causing your pain.  The main symptom of period pain is 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 are a normal part of your menstrual cycle and can usually be treated at home. This is known as primary dysmenorrhoea.

The period pain occurs when the muscular wall of the womb (uterus) 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 to your womb. Your blood vessels help carry oxygen to the organs and tissues within your body. 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. This is known as secondary dysmenorrhoea. These conditions include the following:

• 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. For more information.
• Fibroids: this condition occurs when non-cancerous (benign) tumours grow in the womb. They can make your periods heavy and painful. For more information.
• Pelvic inflammatory disease: your womb, fallopian tubes and ovaries become infected with bacteria, leaving them severely inflamed (swollen and irritated). For more information.
• 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): 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 secondary dysmenorrhoea, 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 secondary dysmenorrhoea as you get older. Most women affected by secondary dysmenorrhoea are between 30 and 45 years of age.

Secondary dysmenorrhoea 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 (incision) is made in your abdomen through which a thin, flexible microscope 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.
• Hysteroscopy: this test allows your specialist to look inside your womb using a thin telescope device known as a hysteroscope. The hysteroscope is carefully passed through your vagina and into the womb to look for any abnormalities.