Lymph Node On One Side Of My Neck Is Swollen.

Lymph node on one side of my neck is swollen. It generally doesn't hurt, but when I use my jaw a lot (like when eating or speaking for long periods), it hurts like a dull achy pain. I don't have any symptoms of NHL or Hodgkins Lymphoma, but this is annoying and slightly painful. It almost feels like a cramp in that muscle under my jaw. Any thoughts on cause and treatment?