Numbness of the left bunion may be caused by trauma, infection, lumbar spine pathology and other reasons. 1. Trauma: When the left bunion is hit, crushed, cut, etc., the peripheral nerves are edematous and broken due to external stimulation, which causes numbness of the left bunion, in addition to swelling and bruising of the skin. 2. Infection: When the left bunion is infected by bacteria or fungus, it can invade the peripheral nerves of the left bunion, resulting in inflammation of the nerves and causing numbness of the left bunion, as well as neuropathic pain. 3. Lumbar spine lesions: When lumbar spine has lumbar disc herniation, lumbar spinal stenosis, lumbar spine tumor, lumbar spine slippage and other related diseases, it can cause lumbar spine to compress the nerve root, which will lead to numbness of the left toe. The cause of left bunion tingling cannot be accurately determined based on the symptoms alone, but needs to be combined with the characteristics of the medical history and other test results to make an accurate judgment, and it is recommended that the cause of the disease be clarified under the guidance of a doctor.