How long does mono last?

Symptoms of mono typically last for two to four weeks, according to Teens Health. However, many people feel the tiring effect of the virus on the body for several weeks longer, making resting very important. Once someone overcomes mono, the virus remains dormant in the body for life.

Mono, short for mononucleosis, is caused by the Epstein-Barr virus, according to Teen Health. After a person is infected, the virus typically incubates in the body for four to seven weeks before it causes illness. Mono causes headaches, weakness, tiredness and a sore throat. Mono has no cure as of November 2014, and the virus must run its course in the body naturally.