My 2 yr. old son has a swollen lymph node on the left side of his neck?

Yes??: What's the question? If it doesn't seem to be bothering him you can observe. He may have the beginning of an ear infection or a throat infection but he will let you know by his untoward behavior. At that point you can call back for further guidance if needed.

Lymph node: on one side of the neck, common, if small, moving , soft nontender, no need to worry, usually stays there for some time after throat infection, if otherwise, ask your son's pediatrician to examine on the next visit and follow up with, take care

Usually is benign: Lymph nodes are located throughout the body & generally noticable in exposed areas like the neck. They are usually pea sized at rest and enlarged when stimulated by bug bites, dermatitis, drainage or infection. They rarely can become damaged by infection & grow to golf ball size & need drainage or removal. Most enlarge and later shrink back down within a 3 wk cycle unless chronically stimulated.