Talk to Internal Medicine on Swollen Lymph Nodes

what causes swollen lymph nodes? is there a link between swollen lymph nodes and fibrocystic breast tissue? Are swollen lymph nodes caused by an infection? she had a uti due to copper t and an infection in her throat for which she took medicines but didn't complete the course what are the side effects of not completing antibiotics course? she has swollen lymph nodes in her leg