Some develop no noticeable symptoms and many develop mainly annoying ones for a few weeks to a few months. I had the misfortune to develop symptoms from infecti

Some develop no noticeable symptoms and many develop mainly annoying ones for a few weeks to a few months. I had the misfortune to develop symptoms from infectious mononucleosis shortly after minor surgery. My GP and surgeon kept giving me antibiotics and sending me back to uni. Finally after several months of fatigue, nausea, and depressed appetite I wandered into campus health jaundiced with a 104º F fever and a temporarily enlarged liver. I ended up withdrawing from that semester and retroactively from the previous one. I was ordered into a month of bedrest and half a year of decreased physical activity while recovering. So I guess we could say there's a wide range of severity, partly depending on how soon it's addressed.