Loss of sensation in the left middle toe may be caused by physiological reasons such as localized pressure, or pathological reasons such as localized lesions of the middle toe, lumbar spine lesions, peripheral neuritis and so on. 1. Physiological reasons: improper posture for a long time may cause the left middle toe to be compressed, resulting in local blood circulation obstacles, thus causing numbness of the nerve and insensibility, which can generally be restored after appropriate rest. 2. Localized lesions of the middle toe: if the middle toe is traumatized or infected, it may affect the nerves there, and the symptoms of insensibility may appear. 3. Lumbar spine lesions: such as lumbar spinal stenosis, lumbar disc herniation, etc., which compresses the nerves and can also lead to symptoms of insensibility in the toes. 4. Peripheral neuritis: diabetes, vitamin B deficiency, chronic alcoholism and other diseases can cause peripheral neuritis, causing damage to the peripheral nerves, causing symptoms of middle toe insensibility. There are other reasons for the lack of sensation in the middle toe of the left foot, if the rest does not relieve or other symptoms, it is recommended to consult a doctor in a timely manner, complete the relevant examinations, a clear diagnosis, and then follow the doctor’s instructions to receive the appropriate treatment, so as to avoid delays in the condition.