I have a small lump under my arm about 2inches above my elbow the size of a pea. Ive had it for about a year but the size back then was barely noticeable when touched. Now its a little bothersome and feels like it could be affecting a nerve because my arm will feel tingly at times and slightly hurt. What could this possibly be?
HI. Usually this is lymph node, and being close to the nerve you get the feeling of tingling. Get clinically checked by your Doctor. Also needed is routine and special blood tests like V Chat Doctor.  High resolution ultrasonography and FNAC=fine needle cytology can help the diagnosis.