What does it mean if you have no reflexes in left or right arms? endo doc hit both arms and no reaction. but both legs reacted very quickly

Nothing: If you are not having any problems and this was routine exam, as long as both arms reacted the same it means nothing. Often the reaction in the arms is very subtle and while it can be felt by the examiner it will not be as visible as the reaction in the knees.

Arm reflex: You are most probably normal. Sometimes it is difficult to find the reflexes. Recheck next time you see your doctor.