Burning sensation in the left thigh consider lateral femoral cutaneous neuritis, lumbar disc herniation, herpes zoster, diabetic neuropathy. 1. Lateral femoral cutaneous neuritis: due to trauma or strain injury caused by lateral femoral cutaneous nerve entrapment can cause sensory impairment of the lower limbs, numbness, burning sensation, pain and other symptoms. 2. Lumbar intervertebral disc herniation: osteophytes or herniated nucleus pulposus compressing the nerves can cause sensory disorders in the lower limbs, resulting in burning sensation, numbness and other symptoms. 3. Herpes zoster: Herpes zoster can cause localized burning sensation and severe pain by invading the nerves. 4. Diabetic neuropathy: diabetes involving peripheral nerves can appear burning sensation of the lower extremities, ants sensation, and pain and temperature sensation loss. If the burning sensation in the left thigh persists without relief, go to the hospital to check the specific cause, and treat the cause.