The following are common causes of hidden pain in the left posterior lumbar region in men: 1. strain on the muscles of the left posterior lumbar region, the strain is not very serious and not very large, and the corresponding inflammatory reaction stimulates the symptoms of hidden pain. 2. disorders in the small joints of the lumbar region, for example, when exercising vigorously or changing position rapidly, resulting in imbrication of the synovial membrane of the small joints, the local synovial membrane cannot be reset, resulting in hidden pain. 3. 3.It can be seen in the degeneration and hyperplasia of the lumbar spine, such as osteophytes and degeneration in older people, and the corresponding local spinal stability will be weakened, resulting in the symptoms of hidden pain after activities. 4.The presence of visceral system diseases, such as urinary tract infection or stones, can also lead to the symptoms of hidden pain in the left posterior lumbar region.