It is usually the back itselfStrong evidence
For nearly all low back pain, in women as in men, no single damaged structure can be found, and only a small proportion has a cause such as a fracture, cancer or an infection. The NHS names a pulled muscle as a common cause. In 1,172 people with new back pain in Australian primary care, 11 (0.9%) had a serious cause, 8 of them spinal fractures.
Women do report more back pain than men, at every age: in 2020 the worldwide rate was about 9,330 per 100,000 women against 5,520 per 100,000 men, with the biggest gap after 75, and an earlier review of 165 studies found the most back pain in women and in people aged 40 to 80. These are estimates modelled from population data, and the reasons are debated. Nothing in them suggests women's backs are weaker or need gentler exercise: 59% of the people in the 249 exercise trials behind the plan on this page were women.
Sources 1, 2, 3, 4, 5, 6
Periods, endometriosis and the womb
Period pain is cramping in the tummy that can spread to the back and thighs, usually just before or at the start of a period, and it usually lasts up to 3 days. Painful periods affected 16% to 91% of women of reproductive age in community studies, and severe pain 2% to 29%. They tend to ease with age, after having children and with the contraceptive pill, and a review found that women with painful periods are more sensitive to pain even between periods.
Endometriosis affects about 1 in 10 women and people assigned female at birth of reproductive age. It can cause pain in the lower tummy and back, severe period pain that stops you doing your normal activities, heavy periods, pain when peeing or pooing, and pain during or after sex. In the UK it takes 9 years 4 months on average from the first GP visit to a diagnosis, and the World Health Organization (WHO) puts the usual delay at 4 to 12 years. The National Institute for Health and Care Excellence (NICE) asks GPs not to rule it out because an examination or an ultrasound scan is normal. Symptoms overlap with other pelvic problems: in 473 women having keyhole surgery, 30% or more had pelvic pain whatever was found. Very rarely, endometriosis on the sciatic nerve causes leg pain that comes with periods.
Fibroids, common non-cancerous growths in the womb, can cause lower back pain alongside heavy or painful periods, tummy pain and needing to pee more often. The NHS describes adenomyosis, ovarian cysts and pelvic inflammatory disease with pain low in the tummy or pelvis rather than in the back, though its pelvic pain page says pelvic pain can be felt in the lower back too.
Sources 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21
Pregnancy and the year after the birth
More than two-thirds of pregnant women have low back pain, and almost 1 in 5 pelvic pain. About half of back and pelvic pain in pregnancy is pelvic girdle pain, a third is low back pain and a sixth is both, and about a quarter of women still have one or both after the birth, with serious problems in about 7%. The NHS says back pain in pregnancy is very common, especially early on, and that backache can also be a sign that labour has begun.
After the birth, lifting, bending and feeding a baby add load, and the NHS has practical tips for each. In a Cochrane review of 40 trials with over 11,000 women, an epidural in labour made no difference to long-term backache.
The NHS says ligaments soften in pregnancy, which can strain the joints of the back and pelvis. But relaxin, the hormone usually blamed, didn't match who got pelvic girdle pain in 3 of 4 high-quality studies, and in 35 pregnant women the joints loosened without tracking hormone levels or joint pain. Softening happens, but it doesn't explain who hurts, and it isn't a reason to stop moving.
Sources 22, 23, 24, 25, 26, 27, 28, 29
The menopause and your bonesMixed evidence
Women lose bone quickly in the first few years after the menopause, and an early menopause (before 45) or having the ovaries removed raises the risk of osteoporosis. With thin bones, a spinal fracture can follow a minor fall, a lift, or even a cough or sneeze. NICE says spinal fractures are the commonest osteoporotic fracture and often go undiagnosed because people have no symptoms, and the Royal Osteoporosis Society says they are stable and don't cause paralysis. Spine X-rays found one in 18% to 26% of European women, depending on the region, and in 20% to 24% of White North American women aged 50 or over. In one US population, clinically diagnosed spinal fractures were twice as common in women as in men, and 83% followed moderate or no trauma.
Whether the menopause itself causes back pain is unsettled. In 11,332 Norwegian women, the age at menopause wasn't linked with long-lasting back pain, and women using menopausal hormone therapy had more long-lasting back pain over the next 11 years, not less. The idea that the menopause explains women's higher rates remains a hypothesis. The NHS lists muscle aches and joint pains among menopause symptoms, and hormone replacement therapy (HRT) helps prevent osteoporosis, especially after an early menopause, but it isn't a treatment for back pain.
Sources 30, 31, 32, 33, 34, 35, 36, 37, 38, 39
The kidneys, the bladder and other causes
Urine and kidney infections are more common in women. A kidney infection causes pain in the lower back or side, usually just under the ribs, with a high temperature, feeling sick, burning or frequent peeing and dark or cloudy pee, and it needs an urgent GP appointment or NHS 111. A kidney stone causes severe pain that comes and goes, starting in the side or lower back and sometimes spreading to the groin or the area around the opening of the vagina.
Inflammatory back pain (axial spondyloarthritis) affects a similar number of women as men, NICE says, but across 42 studies women waited 8.8 years for a diagnosis against 6.5 years for men. Back and buttock pain that started before 45, wakes you in the second half of the night and eases with exercise needs a GP.
In a survey of 38,050 Australian women, those who often leaked urine had more than twice the odds of frequent back pain, a stronger link than weight or activity; a survey like this shows a link, not a cause. Rarely, back pain comes from the heart (in women, heart attack pain can spread to the upper back), the aorta, an infection or cancer.
Sources 40, 41, 42, 43, 44, 45, 46, 47, 48
When a scan or test helpsStrong evidence
Ordinary back pain doesn't need a scan: NICE advises against routine imaging, and NHS inform says most back problems don't need an X-ray or magnetic resonance imaging (MRI) scan. Scan findings are common without pain: disc bulges were found in 30% of pain-free 20-year-olds and 84% of 80-year-olds.
Tests answer specific questions: a urine test for a suspected kidney infection; a pregnancy test if you could be pregnant; an ultrasound scan for suspected endometriosis or fibroids, with referral to a specialist still possible if it is normal; a computerised tomography (CT) scan for a suspected kidney stone, or an ultrasound in pregnancy; and an X-ray, or a spine check with a bone density scan, for a suspected spinal fracture. NICE suggests considering that spine check whenever a woman of 60 or over has a bone density scan.
Sources 49, 50, 51, 41, 13, 17, 43, 31
How it usually goesStrong evidence
New back pain usually improves a lot within 6 weeks: across 33 studies, average pain fell from 52 out of 100 to 23 at 6 weeks and 6 at a year, and an NHS physiotherapy leaflet says most new low back pain improves within 6 to 8 weeks. It often comes back: 69% of people who had recovered had another episode within a year. Period pain lasts up to 3 days a cycle. Back and pelvic pain from pregnancy usually settles after the birth, though about a quarter of women still have some. A spinal fracture heals in 6 to 12 weeks, in its new shape. Endometriosis symptoms usually stop after the menopause, though not always. No one can promise a timescale.
Sources 52, 53, 54, 7, 23, 55, 10
