The causes of tingling at the tip of the left index finger may be peripheral circulatory disorders, peripheral neuritis, carpal tunnel syndrome, cervical spondylosis, rheumatoid arthritis and so on. 1. Peripheral circulatory disorders: the peripheral circulation and peripheral nerves are densely distributed in the fingertips, and if the peripheral circulatory disorders are caused by vascular injuries, diabetes, etc., the tingling sensation will appear in the fingertips. 2. Peripheral neuritis: long-term stimulation of the peripheral nerves at the fingertips may cause inflammatory edema, resulting in tingling at the tip of the index finger. 3. Carpal Tunnel Syndrome: Carpal Tunnel Syndrome can compress the median nerve, if the nerve is too sensitive, there will be a tingling sensation at the tip of the index finger. 4. Cervical spondylosis: Neurogenic cervical spondylosis compresses or stimulates the nerve roots, which may cause tingling at the fingertips, accompanied by neck and shoulder pain, as well as radiating pain and numbness in the upper limbs. 5. Rheumatoid arthritis: Rheumatoid arthritis manifests as pain in the interphalangeal joints, morning stiffness, etc., and tingling at the fingertips may also occur. Tingling in the tip of the left index finger may also have other causes, such as onychomycosis, finger infections, etc. It is recommended to go to the hospital in a timely manner, complete the relevant examinations, identify the cause of the disease and follow the doctor’s instructions for targeted treatment, so as to avoid delays in the condition.