and numbness in arms can be caused by various medical conditions like
diabetic peripheral neuropathy
abnormal levels of calcium,potassium etc
low levels of VIT B 12,
Other causes could be compression of nerves at the cervical level or there could be local problems like..
Carpal tunnel syndrome
Cubitus tunnel syndromeRadial tunnel syndrome
You must consult a neurologist
and get yourself thoroughly examined and investigated because treatment would depend upon finding the cause and then giving proper and relevant treatment.