Read about signs of mono
The most commonly used diagnostic criterion is the presence of 50% lymphocytes with at least 10% atypical lymphocytes (large, irregular nuclei), while the person also has fever, pharyngitis and adenopathy. Furthermore, it should be confirmed by a serological test. The atypical lymphocytes resembled monocytes when they were first discovered, thus the term “mononucleosis” was coined.
Not everyone who is exposed to EBV develops the signs of mono, though. As with many viruses, it is possible to be exposed to and infected with EBV without becoming sick.
Infectious mononucleosis, “mono,” “kissing disease,” and glandular fever are all terms popularly used for the very common infection caused by the Epstein-Barr virus (EBV). EBV is a member of the herpesvirus family. The characteristic symptoms of infection with EBV include fever, fatigue, malaise, and sore throat.