What Causes Pins And Needles And Burning Sensation In Shoulders?

for the last 3 months i have been experiencing a weird sensation in my left shoulder. it starts with pins and needles then progresses to a burning sensation and results in my shoulder being numb for a period of time. throughout the last 3 months is has been happening more regularly and now my shoulder is almost always experiencing one of those 3 sensations. I hve looked online as to what this can be and have come across parethesia. what would you suggest i do? i have read that the underlying symptoms of parathesia can be very serious and i am now extremely worried.