Period Cramps: How to Relieve Them and When to See a Doctor
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A dull ache in your lower belly, sharp twinges reaching into your lower back, the urge to curl up under the covers… Period cramps are one of the most common period symptoms. Good news: several simple, science-backed methods can relieve them. Here's what actually works, how to time anti-inflammatories properly and the signs that mean you should see a doctor.
In short
- Cramps are mainly caused by substances called prostaglandins, which make the uterus contract.
- They usually last 1 to 4 days, according to the SOGC, and are often strongest at the start of your period.
- The best-supported methods: heat on your belly, physical activity and anti-inflammatories (ibuprofen, naproxen) taken a day or two before your period.
- See a doctor if the pain stops you from living normally, if over-the-counter medicines don't help or if your periods become more painful than before.
Why do we get period cramps?
During your period, the lining of the uterus sheds. According to the Merck Manual, "primary" cramps (with no underlying condition) are thought to come from the release of prostaglandins. These substances make the uterus contract, a bit like during labour, which reduces blood flow to the uterus and causes pain. Women with primary cramps have high levels of prostaglandins.
According to the Merck Manual, the pain can start a few days before your period, is often at its worst about 24 hours after bleeding begins and eases after 2 or 3 days.
Who is more at risk?
Also according to the Merck Manual, cramps are more common in people who got their first period early, who have long or heavy periods, who are under 30, who have never been pregnant, who smoke or who have a family history of painful periods. Stress and anxiety are also among the associated factors. And it's not a minor discomfort: cramps interfere with daily activities in 30% or more of women.
How to relieve period cramps: what works
| Method | How to use it | What the sources say |
|---|---|---|
| Heat | Hot water bottle or warm compress on your belly, warm bath or shower | Recommended by the SOGC, the NHS and the Merck Manual |
| Massage | Gently massage your belly and lower back | Suggested by the NHS and the Merck Manual |
| Physical activity | Walking, yoga, swimming, cycling, at your own pace | May greatly reduce pain, according to Cochrane (low-quality evidence) |
| Anti-inflammatories (NSAIDs) | Ibuprofen or naproxen, started 1 to 2 days before your period | Recommended by the SOGC and the Merck Manual |
| Hormonal contraception | Pill, patch, ring, injection or hormonal IUD, by prescription | Can significantly reduce cramps, according to the SOGC |
1. Heat, your best friend
According to the SOGC (Society of Obstetricians and Gynaecologists of Canada), taking a warm bath or using a hot water bottle or heating pad on your belly helps relieve cramps. The NHS, the UK's public health service, recommends wrapping the hot water bottle in a towel to avoid burns. The Merck Manual also mentions moist heat applied to the abdomen.
2. Move, even gently
A Cochrane review published in 2019, which analyzed trials involving 632 participants, concluded that exercise may provide a large reduction in period pain intensity compared with no treatment. The authors note that the quality of the evidence is low: more studies are needed. The NHS suggests gentle activities like yoga, swimming, walking or cycling. It adds that not smoking and cutting down on alcohol may also help.
3. Anti-inflammatories, at the right time
Non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen and naproxen, are available over the counter at the pharmacy. According to the SOGC, they are most effective if you start taking them a day or two before your period is expected. The Merck Manual recommends starting them 24 to 48 hours before your period and continuing for the first 1 or 2 days. Tracking your cycle helps you plan the right timing.
Always follow the dose on the package and ask your pharmacist for advice, especially if you have other health problems or take other medications.
4. When that's not enough: talk to a professional
If home remedies aren't enough, a doctor or nurse practitioner can suggest other options. According to the SOGC, hormonal contraception (pill, patch, ring, injection or hormonal IUD) can significantly reduce cramps. The NHS also mentions other prescription anti-inflammatories and TENS (transcutaneous electrical nerve stimulation), a small device that uses mild electrical impulses to reduce pain.
Period cramps: when should you see a doctor?
Some pain during your period is common. But pain that knocks you out every month isn't "normal" and deserves to be taken seriously. According to the SOGC and Nova Scotia's 811 line, see a doctor if:
- over-the-counter pain relievers don't help;
- the pain keeps you from school, work or your usual activities;
- you have pain at times other than your period;
- your periods became painful later in life when they weren't before;
- you notice unusual discharge or bleeding.
The NHS adds that you should see a doctor if your periods become more painful, heavier or irregular. This "secondary" pain can be linked to a health problem. According to the SOGC, endometriosis is one of the most common causes of very painful periods. The NHS also names adenomyosis, fibroids, pelvic inflammatory disease and an IUD in the first 3 to 6 months after insertion.
If your periods are also very heavy, read our article Heavy periods (menorrhagia): causes, signs and when to see a doctor. In Quebec, you can call Info-Santé at 811 to speak with a nurse at any time.
Cramps and heavy flow: staying comfortable
Cramp days are often also your heaviest-flow days. Comfortable protection lets you lie down with your hot water bottle, curl up or take a nap without keeping an eye on your sheets.
Our heavy flow period boxer has a full-coverage cut, ideal for resting or sleeping, with up to 12 hours of protection in a soft, breathable, odour-fighting fabric. Discover our full heavy flow period underwear collection, designed in Quebec. For tough nights, our tips are in Period underwear overnight: how to sleep without leaks. And to find out if your flow is in the normal range, read Menstrual flow: how much blood do you lose?
Frequently asked questions
How long do period cramps last?
According to the SOGC, period pain lasts about 1 to 4 days. Nova Scotia's 811 line says 1 to 3 days. Cramps are often strongest at the start of your period.
Is it normal to have cramps before your period?
Yes. According to the Merck Manual, the pain can start a few days before bleeding begins. If you have pain at other times in your cycle, talk to a health professional.
Are period cramps worse in the teen years?
According to the Merck Manual, primary cramps usually start in adolescence and are more common before age 30. Missing school every month because of the pain is a good reason to see a doctor. Our guide Period underwear for teens can also help.
In summary
Period cramps come from uterine contractions triggered by prostaglandins. To relieve them: heat on your belly, some movement, and anti-inflammatories started before your period. If the pain stops you from living normally or changes over time, see a doctor: treatments exist, and a cause such as endometriosis sometimes needs to be ruled out.
References
- Society of Obstetricians and Gynaecologists of Canada (SOGC), Menstrual Pain and Other Symptoms (YourPeriod.ca, 2018): pain lasting 1 to 4 days, heat, NSAIDs taken a day or two before your period, hormonal contraception, when to see a doctor, endometriosis.
- Merck Manual Consumer Version, Menstrual Cramps (2026): role of prostaglandins, timing of pain, risk factors, NSAIDs 24 to 48 hours before your period, heat and massage.
- NHS, Period pain (2026): heat, massage, gentle exercise, smoking and alcohol, TENS, possible causes, when to see a doctor.
- Cochrane, Exercise for dysmenorrhoea (systematic review, 2019): exercise may provide a large reduction in period pain intensity (632 participants, low-quality evidence).
- 811 Nova Scotia, Dysmenorrhea (2023): how long cramps last, home care and signs that mean you should see a doctor.
This article is for information only and does not replace advice from a health professional. If in doubt, see your doctor or call 811 (Info-Santé in Quebec).