Hello and welcome to the forum. Just to clarify, we may be having some wrong words used in your post. By swallowing, do you mean swelling? Lymph nodes do enlarge and 'react' at times as part of the lymphatic system. They are supposed to. It would mean your body is fighting something off and nothing serious. I'm not sure where you are finding a lymph node or if what you are feeling is actually a lymph node if you say it is on your head. Lymph from your head is filtered to the neck lymph nodes typically. We can also get small cysts on our scalp. They are also normally harmless.