Lumbar spinal stenosis is a clinical diagnosis of pain in the buttocks or lower extremities, with or without back pain. Symptoms increase with walking, and patients find relief when sitting or flexing the spine. Clinical care and research are complicated by the heterogeneity of the condition and high rates of anatomic stenosis on imaging studies in older people, who are completely asymptomatic. In Denmark, most patients with mild to moderate symptoms are treated in primary care. Patients with severe disability and no effect of non-surgical treatment may need referral to secondary care and surgery.