Back pain at night: causes, red flags and when to get it checked

When we lie down, the spine and discs are loaded differently, muscles are inactive and gentle movement stops. Joints that are stiff or inflamed ache more. Pain that is present regardless of position, or that is unrelenting, raises the question of something other than a mechanical cause.

• Mechanical back pain with poor posture, an unsupportive mattress or sleeping position, and muscle strain.

• Osteoarthritis of the facet joints and degenerative disc disease, with stiffness after rest.

• Disc prolapse and spinal stenosis, with leg symptoms.

• Inflammatory back pain (axial spondyloarthritis): onset under 40, gradual, improves with exercise not rest, night pain, morning stiffness.

• Osteoporotic vertebral fracture, particularly in older adults, postmenopausal women or long-term steroid users.

• Referred pain from the kidney, gallbladder, pancreas or aorta, and endometriosis or gynaecological causes.

• Spinal infection (discitis, osteomyelitis) with fever and severe pain.

• Spinal tumour or metastases, particularly with a history of cancer, weight loss and unrelenting pain.

Pain that wakes you and is unrelieved by position, fever or chills, unexplained weight loss, a history of cancer, intravenous drug use or immunosuppression, progressive leg weakness, saddle numbness, new bladder or bowel changes, and age over 55 with new pain are red flags.

• Call 999 or go to A&E: new bladder or bowel loss, saddle numbness or rapidly worsening leg weakness.

• Same-day GP or NHS 111: severe night back pain with fever, or a history of cancer with new spinal pain.

• GP within days: unrelenting night pain, weight loss or leg weakness.

• GP or physiotherapy within weeks: night stiffness with a mattress or sleep position issue.

The doctor asks when pain started, whether movement or rest helps, morning stiffness, night waking, leg symptoms, fever, weight loss, cancer history, eye or skin problems, bowel disease and family history. They examine spine movement, tenderness, hips, sacroiliac joints, leg strength, reflexes and sensation.

• Blood tests: inflammatory markers (CRP, ESR), full blood count, bone profile and HLA-B27 where inflammatory disease is suspected.

• MRI spine or sacroiliac joints: the key imaging for inflammatory, infective or tumour causes.

• X-rays: for fractures and degenerative change.

• Bone density scan: where osteoporosis is suspected.

• CT or other imaging: for suspected tumour or vascular causes.

Try a medium-firm mattress, a pillow between the knees if you sleep on your side or under the knees if on your back, and avoid sleeping on your front. Gentle stretching before bed and regular exercise during the day help. Heat packs and simple painkillers ease pain. Do not ignore pain that wakes you.

The NHS route is a GP and physiotherapy, with rheumatology for inflammatory causes. Private physiotherapy, rheumatology and MRI are available directly.