Hi, you may be suffering from Carpal Tunnel Syndrome
, its entrapment of Median Nerve
in the carpal tunnel ( an EMG- NCV test or Electromyography- Nerve Conduction test is recommended for confirmation of this condition) A surgical release of the Flexor Retinaculum at wrist can be curative. The other possibility is of a Peripheral Vascular Disease
(especially if you are a smoker) can be confirmed by a Colour Doppler test.