What Causes Pain In Arm And Numbness In Hand?

I HAVE SHARP PAINS IN MY RIGHT ARM SEEMS TO BE IN THE FLESHY PART OF MY ARM IT USUALLY WAKES ME UP AT NGHT. ASPERIN AND TYLENOL DONT SEEM TO HAVE MUCH AFFECT. ALSO WITH THIS IS A NUMBNESS IN MY HAND. NO CHEST PAINS . BEEN GOING ON FOR ABOUT THREE WEEKS AND GETS A LITTLE WORSE EACH DAY DOCTOR STARTED ME ON AVAMYS NASAL SPRAY TWO MONTHS AGO I AM 57 YEAR OLD MALE