My baby is a month old and a couple of days ago i was massaging his neck and i felt a little lump on the back of it. what does it mean?

Time to see your doc: While this may be nothing, it can only be properly diagnosed by examination. The list of possibilities includes things like swollen lymph glands, small subq fat (lipoma) , cysts, . So the best thing to do is see your pediatrician for a good exam.

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.