What Causes Twitching Sensation In Arm And Fingers?

im experiencing pins and needles on the inside of one arm from the elbow to the tips of my fingers which is made worse when extending the arm, also have infrequent twitching on the inner part of the arm this is not the first time its happened but its does concern me, im 22, 9 stone and 5ft 5. I have history of mental health and fast heart rate