Period pain

Around four in every five women have period pain and nausea at some time in their life. For one in 10 women, it is severe enough to affect their daily activities, such as preventing them from going to school or work. 

Everyone experiences pain differently but persistent discomfort each month could be a sign of something that can be treated. 

Period pain is usually experienced as painful muscle cramps in your tummy area, which can spread to your back and thighs. Pain can vary from one period to the next, with some periods causing no or minimal discomfort and others causing severe pain. Some women may also experience pain in their pelvic area in between periods. Pain can be constant and dull, or intense and in spasms.

Period pain is also known as dysmenorrhoea or menstrual cramps.

The muscles of your womb (uterus) continually contract and relax in waves but you usually can't feel it. During your periods, these contractions are stronger to help the lining of your womb shed away, resulting in the blood loss seen during a period. The contractions are triggered by hormones called prostaglandins.

When your womb contracts, it compresses the blood vessels that line it and temporarily stops the flow of blood and oxygen to your womb. The tissues of your womb react by releasing chemicals that cause pain. These chemicals also cause prostaglandins to be released, which make your womb contract even more — this increases the pain you feel. 

The exact cause of most period pain is unknown. It may be that some women have a greater build-up of prostaglandins than others, causing stronger and more painful contractions.

Period pain can be caused by a medical condition although this is less common and usually affects women aged 30–45. Medical conditions include: 

• Adenomyosis — cells of the womb lining grow into the womb muscle, causing painful periods
• Endometriosis — cells that normally line the womb grow in other places, such as in the fallopian tubes and ovaries; when these cells are shed, they cause severe pain 
• Fibroids — non-cancerous tumours that grow in or around your womb, causing heavy and painful periods
• Pelvic inflammatory disease — severe inflammation of your womb, fallopian tubes and ovaries caused by an infection with bacteria

Period pain can also be caused by contraceptive devices. An IUS (intrauterine system) can cause period pain, especially in the initial months after insertion. The period pain you experience may be different if it is caused by a contraceptive device eg more severe or lasting longer. You may also have:

• A thick or foul-smelling vaginal discharge
• Bleeding in between periods
• Irregular periods
• Pain during sex

There are two types of period pain — primary and secondary dysmenorrhoea.

Primary dysmenorrhoea

This is the most common type of period pain and does not involve any underlying problems with your pelvis or womb. Symptoms include: 

• Cramps spreading to the back of your thighs
• Dull constant pain
• Intense spasms of pain
• Stomach cramps

It's most common in your teens and early twenties.

Secondary dysmenorrhoea

This is a sign of an underlying medical condition, such as a problem with your pelvis or womb. Symptoms include:

• Heavy periods
• Irregular periods
• Severe pain

It's more likely in your late twenties onwards.

Menstrual cramps differ from premenstrual syndrome (PMS) discomfort.

Primary dysmenorrhoea

The main symptom of primary dysmenorrhoea is cramps in your lower tummy during your periods. It is common not to experience any pain during your first few periods, with pain starting 6–12 months later. Your period pain: 

• May spread to your lower back and/or the top of your legs
• May vary in severity from one period to the next and become less severe as you get older and after having a baby
• Usually starts when the bleeding starts or sometime during the preceding day and lasts for 12–24 hours, or in some cases 2–3 days

In addition to pain, you may experience: 

• Breast tenderness
• Diarrhoea and/or bloating
• Feeling emotional, faint, sick (nausea), tearful and/or tired
• Headaches

The following symptoms are not caused by primary dysmenorrhoea and if you experience them you should see your GP:

• High temperature (fever)
• Pain during sex
• Sudden severe abdominal pain
• Vaginal bleeding after having sex
• Vaginal bleeding in between periods
• Vaginal discharge

Secondary dysmenorrhoea

The main symptom of secondary dysmenorrhoea is cramps in your lower tummy during your periods. You may notice that your periods become more painful after several years of less painful or normal periods. If your pattern of period pain changes, eg becomes more severe or lasts longer, you may have secondary dysmenorrhoea. See your GP if you have the following symptoms:

• Bleeding in between periods
• Heavier bleeding than during past periods
• Irregular periods
• Pain during sex, in between periods and/or in your back passage (rectum)
• Vaginal discharge

Period pain usually starts when the bleeding starts. However, some women have pain up to several days before their period starts. Pain usually lasts 12–24 hours but can last 2–3 days or longer. It is usually most severe when your bleeding is heaviest. 

In young girls, period pain usually starts when they start getting periods. If there is no underlying problem eg with the pelvis or womb, period pain usually improves as women get older and after having a baby.

You should also see your GP if period pain starts to suddenly worsen, or you have any of these symptoms:

• Bleeding between periods
• Vaginal discharge that's discoloured or strong-smelling
• Pain during sex

They may perform an internal examination to check for underlying conditions.

If your period pain has no obvious cause, your GP may refer you to a gynaecologist who may carry out:

• Blood and urine tests
• Ultrasound scan – uses sound waves to form images of the inside of your body
• Laparoscopy – a device is inserted via a small incision in your abdomen to look for underlying conditions

You should see your GP if your period pain starts to suddenly worsen or you have any of these symptoms:

• Bleeding between periods
• Pain during sex
• Vaginal discharge that's discoloured or strong-smelling

Your GP may examine the front of your tummy — in primary dysmenorrhea, the front of your tummy will be normal. They may also check for underlying conditions by performing an internal pelvic examination. With your permission, your GP will insert a gloved, lubricated finger into your vagina and feel for any abnormalities in your ovaries or womb. 

You can ask to have a female doctor perform your internal pelvic examination or have a practice nurse be present as a chaperone. You can also choose a friend or relative to be present during your examination.

If after three months of treatment with painkillers or a suitable hormonal contraceptive, your period pain has not improved, your GP may refer you to a gynaecologist who may carry out:

• Blood and urine tests
• Hysteroscopy — a thin, tube-like telescope is passed through your vagina and into your womb to look for abnormalities
• Laparoscopy — carried out under general anaesthetic, a thin, tube-like telescope is inserted via a small incision in your abdomen to look for underlying conditions and if necessary, take tissue samples 
• Pelvic ultrasound scan — this painless procedure uses high-frequency sound waves to form images of the inside of your body and is used to look for abnormalities with your fallopian tubes, ovaries, vagina or womb

You can try aspirin and ibuprofen for period pain relief as paracetamol may not be as effective. You should not take aspirin if you are aged under 16. 

Your doctor may prescribe a painkiller, such as naproxen or codeine, if over-the-counter medicines don't work.

If you are taking a non-steroidal anti-inflammatory (NSAID), such as aspirin, ibuprofen or naproxen, try to: 

• Take the first dose as soon as your pain or bleeding starts — you can also try taking your first dose the day before your period starts to prevent pain from building up
• Take the tablets at regular intervals during the 2–3 days when your period pain is at its worst but do not take more than three doses in 24 hours; this will provide more consistent pain relief than just taking the tablets when you feel your pain increase
• Take the appropriate dose — if your pain is not relieved, ask your GP or pharmacist if your dose can be increased

If you take NSAID painkillers for a few days in a row during each period, you're unlikely to have side effects. But make sure you’re aware of the possible side effects by reading the leaflet that comes with your tablets.

You should not take NSAID painkillers if you have asthma or kidney, liver or stomach problems.

You could also try:

• A TENS (transcutaneous electrical stimulation) machine
• Exercise (eg walking, swimming or cycling)
• Lightly massaging your lower abdomen
• Relaxation techniques, such as yoga or Pilates, to distract you from  your discomfort or pain
• Stopping smoking
• Warm baths or showers

Certain birth control options can also help with period pain:

• Combined contraceptive pill — this pill thins your womb lining, which makes your periods lighter, and reduces how much prostaglandin your body releases, which is what causes the painful contractions; with a thinner womb lining you won't need such strong contractions to shed your womb lining
• Contraceptive implants or injections — an alternative to the combined contraceptive pill
• IUS — another alternative to the combined contraceptive pill

If your period pain is due to an underlying medical condition, your treatment will depend on the condition; eg pelvic inflammatory disease can be treated with antibiotics and fibroids can be treated with an IUS, medications or surgery. 

Period pain as part of your normal menstrual cycle, which doesn't include symptoms in between periods, will not affect your fertility. However, period pain caused by an underlying medical condition may affect your fertility. For example endometriosis and pelvic inflammatory disease, which both cause period pain, also cause scarring and a build-up of tissue in your fallopian tubes — this makes it more difficult for sperm to reach your eggs