Back Pain During Period: Causes, Relief and When to Worry

Quick answer: why your back hurts during your period

Back pain during your period usually comes from period cramps. The cramps start in your womb and can spread to your lower back and thighs, so the ache you feel in your back often rises and falls with them.

This pain is common, and it usually eases within about 3 days. See a doctor if it stops your usual activities, gets worse each month, or lasts after your period ends. Get help at once if back pain comes with numbness or weakness in both legs, or you cannot control when you pee or poo.

If you are reading this with a sore back right now, heat and an anti-inflammatory painkiller such as ibuprofen are good first steps. The what helps section has more.

Why does my lower back hurt on my period?

Before and during a period, the lining of the womb makes chemicals called prostaglandins. They make the muscles and blood vessels of the womb contract. These contractions are the cramps you feel.

Cramps are felt mostly in the tummy. They can spread to the back too. Some people feel their period mostly as a low, dull ache across the base of the spine. Painful periods can come with back pain and leg pain as well as belly cramps.

Why the first day or two feel worst

Prostaglandin levels are high on the first day of a period. They go down as bleeding continues and the lining is shed. This is why back pain, like cramps, is often at its worst at the start and eases after the first few days.

What common period back pain looks like

Back pain that fits a normal period usually:

Starts just before or at the start of your period
Comes and goes with your cramps
Lasts up to about 3 days
Feels like a dull ache or a tight, heavy feeling low in the back
Gets better with heat and ordinary painkillers

If the pain is hard to live with, treatments can help. They are in the treatments a doctor can offer section.

When back pain can point to endometriosis or adenomyosis

Some period pain comes from a condition in the pelvis. This is called secondary dysmenorrhea. Its pain tends to get worse over time and lasts longer than normal cramps. It may start a few days before a period, get worse as the period goes on, and not go away after it ends. Endometriosis and adenomyosis are two of its causes.

Endometriosis

In endometriosis, tissue similar to the lining of the womb grows in other places, often around the womb, the ovaries and the lining of the pelvis. It can cause pain in your lower tummy and back, severe period pain that stops your normal activities, pain when you poo or pee, and pain during or after sex. The pelvic and back pain can happen at any time in your cycle, including between periods.

Endometriosis is often found on the uterosacral ligaments. These are thick bands of tissue that run from the base of the womb to the lower spine. They are the most common place for deep endometriosis, and endometriosis there is linked to painful periods, long-term pelvic pain and pain during sex.

Endometriosis can take a long time to diagnose, because its symptoms are like those of other conditions. An ultrasound or MRI scan can help, and a laparoscopy (keyhole surgery) can confirm it. The list of endometriosis symptoms and the guide to endometriosis pain vs. normal period pain can help you see where your own pain fits.

Adenomyosis

In adenomyosis, the tissue that lines the womb grows into the muscle wall of the womb. It is one of the causes of painful periods, and it is more common in older women who have had children. If your back pain comes with periods that are getting heavier and more painful, ask your doctor about it. The guide to adenomyosis vs. endometriosis explains how the two differ.

Signs your back pain needs a closer look

Talk to a doctor if your back pain:

Stops you from working, studying or doing your usual activities
Starts more than 5 days before your period, or goes on after it ends
Happens at times other than your period
Is getting worse from one cycle to the next
Comes with pain during sex, or when you poo or pee
Does not get better after 3 months of treatment

What helps back pain during your period

These are the steps most likely to ease period pain, including pain in the back:

Heat. A heat pad or hot water bottle wrapped in a tea towel, or a warm bath or shower. On the back, heat also helps with muscle spasms and stiffness. Do not fall asleep with a heating pad on.
Painkillers. Ibuprofen and naproxen are NSAIDs. They lower the prostaglandins your body makes, which makes cramps less severe. They work best if you take them at the first sign of your period or pain. People with stomach ulcers, a bleeding disorder, liver damage or an aspirin allergy should not take NSAIDs. If you have asthma, check with a pharmacist first.
Massage. Gently massage your tummy and back, or ask someone you trust to rub your lower back.
Gentle movement. Walking, swimming, cycling or yoga can help. Pelvic rocking exercises are another option. Stay as active as you can, and avoid long periods in bed.
Rest in a comfortable position. Lying on your side with your knees bent may help.

Treatments a doctor can offer

If period pain is severe, a GP may suggest stronger anti-inflammatory medicines, a TENS machine, or contraception such as the pill, implant or injection. These thin the womb lining, which makes periods lighter and eases the pain. If a condition such as endometriosis or adenomyosis is causing the pain, treating it helps, and a doctor may refer you to a gynaecologist.

What to track

Back pain is easy to brush off at an appointment. A record over two or three cycles shows your doctor the pattern. Note:

The cycle day, and whether you are bleeding
Where the pain is: low in the back, across the base of the spine, one side or both
How it feels: dull ache, heavy, sharp, or pulling
How bad it is, from 0 to 10, and what it stopped you doing
Whether it spreads to your bottom or legs
Other symptoms, such as pain when you poo or pee, pain during sex, or heavy bleeding
What you took or did, and whether it helped

The guide to a pain diary for your doctor shows how to set this out. The Endolog symptom tracker app lets you log pain by body location next to your cycle and export the record for your appointment.

When to get help

Get emergency help

Call 999 or go to A&E (in the US, call 911 or go to the emergency room) if you have back pain with any of these:

Pain, tingling, weakness or numbness in both legs
Loss of feeling around your genitals or bottom
Changes in your bladder or bowels, such as trouble peeing, or peeing or pooing yourself
Chest pain

Get urgent advice

Ask for an urgent GP appointment, or call 111 in the UK (in the US, call your doctor the same day or go to urgent care), if:

Your period pain or pelvic pain is severe or worse than usual, and painkillers have not helped
You have back pain and feel hot, cold, shivery or generally unwell
You have fever and pelvic pain, or sudden severe pain, especially if your period is more than a week late and you have been sexually active

See a doctor

Book a GP appointment (in the US, see your doctor) if:

Your periods become more painful, heavier or irregular
Period pain stops you from doing your usual activities
You have pain during sex, or when you pee or poo
You bleed between periods
Your back pain is worse at night or does not ease with rest

FAQ: back pain during your period

Is it normal to have back pain during your period?

Yes. Period cramps can spread to the lower back. An ache that comes with your cramps and fades within about 3 days is common.

Why is my back pain worse on the first day of my period?

Prostaglandins, the chemicals that make the womb contract, are highest on the first day. The pain tends to ease as their level falls over the next few days.

Can endometriosis cause lower back pain?

Yes. Endometriosis can cause pain in the lower tummy and back, and this pain can happen at any point in your cycle. Tell a doctor if your back pain comes with severe period pain, pain during sex, or pain when you poo or pee.

When should I worry about back pain during my period?

Get emergency help if back pain comes with numbness or weakness in both legs, numbness around your genitals or bottom, or trouble controlling your bladder or bowels. See a doctor if the pain gets worse each cycle, stops your usual activities, or goes on after your period ends.