Why does my back hurt on my period?
Your back hurts on your period because the uterus contracts to shed its lining, driven by chemicals called prostaglandins. The uterus shares nerve pathways with the lower back, so the cramping pain spreads there. It's usually worst on the first one or two days. Severe or worsening back pain can point to endometriosis, adenomyosis or fibroids.
Why period pain lands in your back
Just before and during your period, the lining of the uterus releases prostaglandins. They make the muscle of the uterus squeeze, which helps push the lining out, but strong squeezes also briefly reduce blood flow to the muscle, which hurts. Pain signals from the uterus travel along nerves that also serve the lower back, so the brain can feel it there too. Doctors call this referred pain.
Higher prostaglandin levels mean stronger contractions and more pain. That's why back pain usually starts a few hours to a day before bleeding and eases after the first 2 or 3 days, when prostaglandins fall.
What helps
| Remedy | How it helps | Evidence |
|---|---|---|
| Anti-inflammatory pain relief (ibuprofen, naproxen) | Lowers prostaglandin production | Strong; works best started at the first sign of pain |
| Heat on the lower back or belly | Relaxes muscle and dulls pain signals | Good; comparable to some pain relief in small studies |
| Gentle movement, walking, stretching | Releases endorphins and eases tension | Moderate |
| Regular exercise across the cycle | May reduce period pain over time | Moderate |
| Hormonal contraception | Thins the lining, so fewer prostaglandins | Strong, for people it suits |
| TENS machine | Blocks pain signals | Some evidence |
Ask a pharmacist about the right pain relief for you, especially if you have asthma, stomach problems or kidney issues. More ideas in what helps period cramps and heat for cramps.
When back pain is not just a period
Period back pain should improve as your period goes on and respond to simple pain relief. If it doesn't, something else may be adding to it:
- Endometriosis: tissue like the uterine lining growing elsewhere, often causing deep pain before and during periods, pain with sex or bowel movements.
- Adenomyosis: lining tissue growing into the uterine wall, often with heavy periods and a bulky, tender uterus.
- Fibroids: benign growths that can press on the back and cause heavy bleeding.
- Pelvic inflammatory disease: infection, often with fever or unusual discharge.
- A back problem: pain that doesn't follow your cycle is probably not period-related.
Back or pelvic pain stops you working or sleeping, doesn't improve with pain relief, is getting worse over the years, lasts after your period ends, comes with heavy bleeding, fever or pain during sex, or started for the first time after age 25. Sudden severe pain, or pain with a positive pregnancy test, needs urgent care.
Pain, sleep and mood
A sore back makes it harder to sleep, and poor sleep makes everything feel harder, mood included. If your first period days are reliably rough, planning a gentler day can help as much as any remedy. Our lower back pain on your period page goes deeper.
Frequently asked questions
Can back pain be a sign my period is coming?
Yes. Many people feel a dull lower back ache a day or two before bleeding starts.
Why does my back hurt more on my period than before?
Pain that is getting worse over time can be a sign of endometriosis, adenomyosis or fibroids. See why periods get more painful.
Is it normal for period back pain to go down my legs?
It's fairly common, because the same nerves are involved. See legs hurt on your period.
What's the fastest way to ease period back pain?
An anti-inflammatory taken early plus heat on your lower back works well for most people.
Sources
- ACOG: Dysmenorrhea: Painful Periods FAQ
- NHS: Period pain
- Cleveland Clinic: Dysmenorrhea
- NHS: Adenomyosis
This page is for information only and isn鈥檛 medical advice. If something worries you, please talk to a doctor.
Keep reading
Lower back pain on your period: why it happens and what helpsLower back pain on your period is common. Why period pain spreads to your back, what eases it (heat, movement, timing painkillers) and when to see a doctor.
Period cramps: why they happen and what actually helpsPeriod cramps explained kindly: why your uterus cramps, how long it lasts, what really helps (timing matters) and the signs that need a doctor.What helps period cramps? Remedies that workWhat helps period cramps? Painkillers, heat, exercise, hormonal options and a few supplements, ranked by evidence. Plus when period pain needs a doctor.
When is period pain not normal?Period pain is not normal when it stops your life, ignores painkillers or keeps getting worse. Red flags for endometriosis, adenomyosis and fibroids.PMS symptom diary: what to track for your doctorHow to keep a PMS symptom diary doctors can use: the daily items, the 1 to 6 rating scale, how long to track, and how to read the chart before your visit.