Mononucleosis, the dreaded "kissing disease," leaves many teens with a fever, swollen lymph nodes and fatigue. But catching it when you're older (and up to 10 percent of adults are susceptible) can be more problematic.
Johns Hopkins Medical Institutions say once you hit your 30s, the symptoms, other than fever, vary widely, making it difficult for physicians to diagnose. Doctors sometimes assume other viruses are to blame.
Fortunately, a simple blood test can reveal the misshapen white cells that are the hallmark of the disease. Caused by the Epstein-Barr virus, 'mono' is spread through saliva.
