Epstein-Barr virus (EBV), is an extremely common virus that most of us contract at some point, often during childhood. Typically, symptoms are mild or largely unnoticeable. However, EBV can cause infectious mononucleosis, leaving one fatigued for weeks or even months.

Once you have EBV, the virus lives in an inactive stage in your body. In some cases, the virus may reactivate, again with few or no symptoms. People with weakened immune systems are more susceptible to EBV reactivation and more likely to develop symptoms. Although usually mild, EBV reactivation can be serious and lead to complications such as nervous system disorders. Chronic EBV infection is linked to cancers including Hodgkin lymphoma, Burkitt lymphoma and cancer of the nose and throat (nasopharyngeal cancer).

Since approximately 90% of us have EBV, testing positive isn’t significant unless you have EBV-like symptoms that can’t be explained by another cause. Your medical provider will sort that out with you. Click here to read what the Centers for Disease Control and Prevention says about EBV.