Thank you for the query.
nodes get painful and enlarged due to inflammation in the area where this lymph nodes are located. As you have not specified where are yours lymph nodes enlarged, it is hard to tell about the possible cause of it.
Lymph nodes can get also enlarged due to some viral infections or hematologic diseases.
Sometimes, lymph nodes get enlarged due to cancer metastases. However such lymph nodes are usually hard, painless and not movable.
If you are unable to localize the source of possible inflammation, I suggest you to visit your doctor, have an ultrasound
of this nodes and one or few of them can be removed and send for histopathology in case of any doubts.
Hope this will help.