Most people recover from mono in 2 to 4 weeks - but fatigue commonly lingers for weeks after other symptoms fade, and occasionally symptoms last six months or more.
Mono is usually Epstein-Barr virus, with symptoms starting four to six weeks after infection: crushing fatigue, fever, sore throat, swollen glands, body aches. There is no antiviral or antibiotic that treats it - rest, fluids, and over-the-counter pain relief are the whole plan, so patience is genuinely the treatment. The one non-negotiable: mono can enlarge the spleen, and a rupture is a medical emergency, so no contact sports or intense exercise for about a month. Seek urgent care for sudden severe left-sided belly pain. Pymander is a free AI doctor, 24/7 by text, and can help you gauge whether your recovery is on track.
What to do
Common questions
How long does mono last?
Most people recover from mono (infectious mononucleosis, usually caused by Epstein-Barr virus) in two to four weeks. The catch is the tail: fatigue can persist for several more weeks after the fever and sore throat fade, and occasionally symptoms stretch to six months or longer. Symptoms typically start four to six weeks after you catch the virus - extreme fatigue, fever, sore throat, swollen glands, body aches. There is no specific treatment and no antiviral shortcut: rest, fluids, and over-the-counter pain relievers are the plan. Two safety rules matter most. First, mono can enlarge the spleen, which can rupture - so no intense exercise or contact sports for about a month, even if you feel fine. Second, avoid aspirin for teens and children with viral illnesses. Get urgent care for sudden severe left-sided belly pain, trouble breathing, or severe difficulty swallowing. Pymander is a free AI doctor, 24/7 by text, that can help you track whether your recovery is following the normal arc.