Pea size hard lump under skins surface. Attached to the tissue or muscle? Doesn't hurt at all. Located at where my elbow is but on the inside part. Moves around when I rub it. Extremely scared!!

Lymph node. Lymph nodes are found throughout the body. The most common ones that can be felt are both in the front and back of the neck, under the armpits and in the groin. One can also find them around the elbows. Any scratch, bite, or infection can make a particular lymph node draining that area, swell. If they continue to grow and persist over six weeks, they need to be evaluated by a physician.