Can lymph nodes swell for no reason on one side of neck ??

Very true!: It can be very common to see the lymph nodes swell in the neck in one or more if something stimulates the immune system such as in the throat , teeth, or even the face area. If an area gets inflamed then it can cause the lymph nodes to react to that response to protect your body from invasion by bacteria. Of course you need to watch it and check if persists or gets much worse. Hope this helps!