There are many causes of low back pain, which can be divided into three main categories-
Mechanical low back pain:
arises intrinsically from the spine, intervertebral disks, or surrounding soft tissues
Ex: Herniated disc, Degenerative disease, Spondylolisthesis, Spinal stenosis, Osteoporosis, Fractures, Congenital disease (Severe kyphosis, scoliosis, transitional vertebra)...etc.
Nonmechanical spine disease:
spine disease caused by other origin
Neoplasia, Infection, Inflammatory arthritis (often HLA-B27-associated), Scheuermann disease, Paget disease
Visceral disease:
Renal disease, Gastrointestinal disease, Pelvic organ disease, Aortic aneurysm, Fat herniation of lumbar space
If you have any relevant problems, please go to a qualified medical facility for evaluation and treatment by healthcare professional.