In real clinical practice, back pain in young patients is associated with neurological manifestations of degenerative changes in the lumbosacral spine. However, such complaints may be a manifestation of a lesion of the sacroiliac joint-sacroiliitis, and degenerative changes in the spine may accompany it, but not cause pain. Sacroiliitis is an inflammatory lesion of the sacroiliac joint, which can develop as an independent disease or as a symptom of another nosology. The causes of this pathology are diverse: injuries, long-term overloading of the joint, congenital abnormalities of the joints, infectious or systemic diseases, and tumors. In neurological practice, sacroiliitis is similar to myofascial syndromes and can disguise as degenerative diseases of the spine, so early diagnosis and proper therapy are of particular importance. Awareness of doctors about the features of examination of young patients, the use of neuroimaging techniques (CT, MRI), laboratory diagnostics, will help to improve the results of therapy. Prescription of NSAIDs with a pronounced anti-inflammatory potential will slow down the progression of the inflammatory process.