Why have I pins and neefles in my left hand all the time?

Nerve compression. See your dr! you may have a compressed nerve in you neck or shoulder. There are other possible causes. You need an exam.
PINCHED NERVE. Concern is a 'pinched nerve' somewhere between neck and hand. One possiblity is a 'cevical radiculopathy' coming from 'pinched nerve in the neck'. A c-spine MRI will help make the diagnosis. Carpal tunnel or ulnar tunnel syndrome is diagnosed with a nerve conduction study (ncs). These mono-neuropathies are caused by pinched nerve in wrist or elbow. Your provider can order these. Hope ur better.