What period pain is
Menstrual cramps, also called dysmenorrhoea, are throbbing or cramping pains in the lower belly that come just before or during a period. The pain can spread to the lower back and thighs. Many girls and women also feel tired, bloated, nauseous or have loose stools or headaches at the same time.
Period pain is very common, especially in teenagers and young women, and often becomes milder with age or after childbirth. Mild discomfort is normal, but pain that stops you from going to school, college or work is not something you simply have to put up with.
Why cramps happen
During a period, the lining of the womb releases natural chemicals called prostaglandins. These make the muscles of the womb tighten and relax to shed the lining. Higher levels of prostaglandins cause stronger contractions, which reduce blood flow to the womb for short moments and cause pain. This is called primary dysmenorrhoea and is not caused by any disease.
Secondary dysmenorrhoea is period pain caused by an underlying condition. Common causes include endometriosis, adenomyosis, fibroids, pelvic infection and, sometimes, a copper IUD. This type of pain often starts later in life, lasts longer than the period or gets worse over time.
Symptoms to note
Keeping a simple diary of your periods and pain for a few months helps both you and your doctor. Note when the pain starts and stops, how strong it is, how heavy the bleeding is, and whether it affects school, work or sleep. Look out for these symptoms in particular.
- Cramping pain in the lower belly, starting just before or with bleeding
- Aching lower back and thighs
- Nausea, vomiting, loose stools or headache
- Very heavy bleeding or large clots
- Pain during sex or passing stools, or pain between periods
How the cause is found
For young women with typical cramps and no other symptoms, a doctor may diagnose primary dysmenorrhoea from the history alone and begin simple treatment. If the pain is severe, new, getting worse or comes with heavy bleeding or other symptoms, the doctor will examine you and may order tests to look for an underlying cause.
A pelvic ultrasound can show fibroids, ovarian cysts or adenomyosis. A haemoglobin test checks for anaemia from heavy bleeding, and swabs may be taken to look for infection. Endometriosis often does not show on a scan and sometimes needs a keyhole procedure called laparoscopy to be confirmed.
Treatment options for menstrual cramps
Non-steroidal anti-inflammatory painkillers (NSAIDs) such as ibuprofen or mefenamic acid work well because they lower prostaglandins. They are most effective when started at the first sign of pain or bleeding, taken with food, following the label or your pharmacist's advice. Paracetamol is an alternative for people who cannot take NSAIDs, such as those with stomach ulcers, asthma worsened by NSAIDs or kidney disease.
If painkillers are not enough, a doctor may suggest hormonal treatment, such as the combined oral contraceptive pill or a hormone-releasing IUD, which makes periods lighter and less painful. These are given only on a doctor's prescription after checking for risks. Underlying conditions like fibroids or endometriosis are treated specifically, sometimes with surgery.
Self-care that helps
Simple measures ease cramps for many women and can be used along with medicine. Start them early in the period. Pregnant women should not take NSAIDs without a doctor's advice, and any belly pain or bleeding in pregnancy should be checked promptly, because it is not period pain.
- Apply a hot water bag or warm compress to the lower belly or back
- Take a warm bath or shower
- Gentle exercise such as walking, stretching or yoga
- Rest and get enough sleep
- Eat regular meals and drink enough water
- Avoid smoking, which can worsen period pain
When to see a doctor for menstrual cramps
See a doctor if period pain stops you from daily activities, does not improve with painkillers, has become worse over months, or began after age 25. Also see a doctor for heavy bleeding, bleeding between periods or pain during sex. A doctor or pharmacist can advise safe pain relief and help find any underlying cause so it can be treated properly.
Medicines doctors commonly use
Only your doctor can decide which medicine, dose and combination is right for you.
- NSAIDs such as ibuprofen or mefenamic acidReduce the chemicals that cause cramps and lower pain.Follow the label or your pharmacist's advice; take with food and avoid in stomach ulcers, kidney disease or pregnancy.
- Paracetamol (pain reliever)Relieves mild to moderate period pain.Follow the label or your pharmacist's advice; do not exceed the stated amount, especially with liver disease.
- Antispasmodics such as drotaverine or hyoscineRelax the muscles of the womb to ease cramping.Use as your doctor or pharmacist advises.
- Combined oral contraceptive pills or hormonal IUDMake periods lighter and less painful.Only on a doctor's prescription after checking for risks such as migraine with aura or clotting problems.
See a doctor urgently if
- See a doctor urgently if you have sudden severe lower belly pain with fainting, especially if your period is late.
- See a doctor urgently if pain comes with high fever, foul-smelling discharge or vomiting.
- See a doctor soon if bleeding soaks a pad every hour or you pass large clots.
- See a doctor soon if period pain is getting worse each month or lasts beyond the period.
- See a doctor soon if you have pain during sex or bleeding between periods.
Tests that may help
This article is general health information, not medical advice. Do not start, stop or combine medicines on your own — always follow your doctor's prescription and ask your pharmacist if unsure.