What Is The Treatment For Pressure In The Arm?

MY RIGHT ARM HAS BEEN FEELING LIKE I HAVE A BLOOD PRESSURE CUP AT THE TOP OF IT FOR ABOUT A MONTH. WHEN I SIT OR BEND OVER ITS WORSE. IF I TURN MY HEAD A CERTAIN WAY ITS WORSE. DON'T KNOW WHAT IT IS COULD IT BE A PINCHED NERVE? BY THE WAY IM FEMALE AND AM 51