My mother has recently been complaining of a stiff neck which seems to have turned into a larger problem. Right about in her tricep area on her left arm it is visibly swollen and when pressure is applied it almost feels like there is fluid or air underneath the skin. It's weird as hell and I can't self diagonose it myself. I was thinking pinched nerve but that swelling and the extent of where the pain runs from her trapezius/neck area all the way down to the upper part of her arm confuses me. She complains of constant stiffness and can't turn her head with aggrevating the pain. This woman is no newbie to pain and I know it must really hurt her if I can visible see at and she is complaining this much, which she never does.

Since I don't trust doctor's much and I value the opinions here I was wondering if anyone had any thoughts to what this could be and how to treat it?

Thanks in advance..