Not Medical Advice: Mono is spread through the exchange of saliva. Anyone is capable of getting it.
As explained by WebMD, mononucleosis, also called "mono," is a common illness that can leave you feeling tired and weak for weeks or months. Mono goes away on its own, but lots of rest and good self-care can help you feel better.
Mono usually is caused by the Epstein-Barr virus (EBV). It is most often seen in young adults. Children can get the virus, but it often goes unnoticed because their symptoms are mild. Older adults usually don't get mono, because they have immunity to the virus.
Mono can be spread through contact with saliva, mucus from the nose and throat, and sometimes tears. Because the virus can be spread through kissing, it has earned the nickname the "kissing disease." If you have mono, you can avoid passing the virus to others by not kissing anyone and by not sharing things like drinking glasses, eating utensils, or toothbrushes.
The most common symptoms of mono are a high fever, a severe sore throat, swollen lymph nodes (sometimes called swollen glands) and tonsils, and weakness and fatigue. Symptoms usually start 4 to 6 weeks after you are exposed to the virus.