My right arm is numb, anyone know what common cause is?

Last week (about 7 days ago) I noticed my arm when numb from the elbow down to my fingers. It feels like my arm is about to fall asleep. I have noticed on and off before this that my last two fingers, especially my pinky finger felt slightly numb. I made an appointment with my Dr, but could only see a nurse. She told me I might be getting Carpal Tunnel and to wear a brace at night and gave me prescription for Naproxen. The Naproxen does nothing but make me tired because of the higher dose and the brace is just uncomfortable and I don't think it's going to help. I am doing what she told me, but I am skeptical of her diagnosis without doing any blood work or scans how can she guess this is the problem? I don't have any pain.. just constant tingling and numbness. Any ideas what else I could try? I read that this could be a vitamin deficiency problem.. I don't know but I am going to go crazy if it doesn't get better soon.