I heard that mono can increase your risk for lymphoma. does the mono just relapse as lymphoma and if so how do you know if it does?

Very low association: Infectious mononucleosis is a very common illness caused by the EBVirus. Serology studies indicate that over 50% of children already show evidence of past infection by age 5, although they may not have had the classic illness of severe sore throat, swollen glands and fatigue. The incidence of Hodgkins lymphoma in adolescents and young adults is 4 per 100.000, so the connection is low at best.

Very unlikely: Epstein Barr virus (EBV), the cause of infectious mononucleosis (mono), also can rarely cause lymphoma. The risk of future lymphoma is somewhat higher in people who have had mono, but still very low. The initial symptom of lymphoma usually is the appearance of one or more painless enlarged lymph nodes. Discuss w/ your doctor, but don't lose sleep over this! It is truly a rare problem.