What are the causes of lower back pain in men?

Low back pain in men can arise from a wide range of anatomical, mechanical, inflammatory, infectious, metabolic, and neoplastic causes. Common musculoskeletal contributors include lumbar strain or sprain—often due to improper lifting, sudden twisting, or repetitive motion—as well as degenerative disc disease, lumbar spondylosis (facet joint osteoarthritis), and spinal stenosis. Herniated or bulging intervertebral discs may compress nerve roots, leading to radicular pain that radiates into the buttock or leg (sciatica).

Structural conditions such as spondylolisthesis (anterior slippage of one vertebra over another) or sacroiliac joint dysfunction are also frequent culprits. Less common but clinically important causes include ankylosing spondylitis—an HLA-B27–associated seronegative spondyloarthropathy that typically presents with insidious-onset inflammatory low back pain, morning stiffness lasting >30 minutes, and improvement with activity—and other spondyloarthropathies like psoriatic arthritis or reactive arthritis.

Infections must be considered, particularly in patients with fever, immunosuppression, intravenous drug use, or recent spinal procedures; vertebral osteomyelitis or discitis often manifests with localized tenderness, systemic symptoms, and elevated inflammatory markers. Malignancy should be evaluated in those with red flags—including age >50 years at onset, unexplained weight loss, night pain, history of cancer, or progressive neurologic deficits—as primary bone tumors, metastases (e.g., from prostate, lung, or renal cancers), or multiple myeloma can involve the lumbar spine.

Referred pain is another key consideration: urologic sources such as nephrolithiasis, pyelonephritis, or prostatic abscess may present with posterior flank or low back discomfort; gastrointestinal etiologies like chronic pancreatitis or diverticulitis can mimic lumbar pathology; and vascular causes—including abdominal aortic aneurysm (especially if pulsatile or associated with hypotension)—require urgent evaluation. Additionally, chronic prostatitis/chronic pelvic pain syndrome may contribute to persistent low back or perineal discomfort in some men.

A thorough history—including onset, duration, aggravating and relieving factors, radiation, associated constitutional or neurologic symptoms—and targeted physical examination are essential for accurate diagnosis. Imaging and laboratory testing should be guided by clinical suspicion rather than used routinely, in accordance with evidence-based guidelines such as those from the American College of Physicians and the American Academy of Orthopaedic Surgeons.