The most common causes of left back pain in men are lumbar muscle strain, trauma, urinary stones, lumbar intervertebral disc herniation, etc. If the pain persists, it is recommended to seek timely medical treatment. 1. Lumbar muscle strain: male patients who have long been engaged in heavy physical labor or long-term poor sitting posture, may cause chronic strain of the lumbar muscles, in the outside world cold stimulation will cause pain in the back of the left. 2. Trauma: If the male patient’s left posterior lumbar area is subjected to external impact, it may cause local muscles, bones, ligaments to be damaged, or lumbar muscle sprains, which may cause pain in the left posterior lumbar area. 3. Urinary stones: If male patients have kidney stones or ureteral stones, when the stones irritate the surrounding mucous membranes or cause obstruction, it is most likely to cause pain in the left posterior lumbar region. 4. Lumbar disc herniation: Lumbar discs will degenerate with age, and the herniated discs may compress the surrounding nerves, resulting in numbness of the nerves and pain in the left lower back. There are many causes of left back pain in men, if the symptoms of left back pain persist without relief, it is recommended to go to the hospital in time to find out the cause of the disease, the doctor targeted treatment.