Could be carpal tunnel syndrome.Often the hand cramps also and bothers one at night.I had it for twenty five years before it got real bad.Raising bars can help. If it persists best to get a real diagnoses.
Best to get a release surgery. I total destroyed my left wrist cartilage
and now I can’t ride a road bike more than ten miles.Go see a hand specialist at a sports clinic.If just carpal tunnel you will be right back on bike very soon.
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