Mono mostly affects people in their teens and 20s. It occurs less commonly in adults over the age of 30. Older adults with mono will usually have a fever but may not have other symptoms such as a sore throat, swollen lymph nodes, or an enlarged spleen.
Mono, or infectious mononucleosis, refers to a group of symptoms usually caused by the Epstein-Barr virus (EBV). Many people develop EBV infections as children after age 1. In very young children, symptoms are usually nonexistent or so mild that they aren’t recognized as mono.
For most people, mono isn’t serious, and it improves without treatment. Still, extreme fatigue, body aches and other symptoms can interfere with school, work and daily life. With mono, you might feel sick for about a month. Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission.
Signs and symptoms such as a fever and sore throat usually lessen within a couple of weeks. But fatigue, enlarged lymph nodes and a swollen spleen may last for a few weeks longer. If you've been experiencing the above symptoms, you may have mononucleosis. If your symptoms don't get better on their own in a week or two, see your doctor.