My son, 19, has a lump on the side/back of his neck and one behind his ear. they are sore to touch. no other symptoms. does he need to be seen?

Should be checked: These sound like lymph nodes which can swell up to fight anything foreign in your system- infection, inflammation, etc. Most are benign, but if they are tender, they should be checked by a doctor.

Probably lymph node: There are several lymph glands located within the structures of the neck & will vary in size from the size of a pea to much larger if stimulated.When stimulated they can enlarge quickly and feel tender to touch or compression. A visit with your dr during regular hours should separate the simple transient issues from those needing further tests.