Health A-Z

Medical Content Created by the Faculty of the Harvard Medical School



The first symptoms of mononucleosis typically include:

  • Fever

  • Headaches

  • Muscle aches

  • Unusual fatigue, such as the need for 12 to 16 hours of sleep daily

These symptoms are followed very shortly by:

  • Sore throat

  • Enlarged lymph nodes

  • Chills

  • Joint aches

  • Loss of appetite and slight weight loss

  • Nausea and vomiting (occasionally)

  • A red rash, usually on the chest. This is more likely if the person has recently taken the antibiotics ampicillin or amoxicillin.

  • Abdominal pain

  • Enlarged spleen

Rare symptoms include:

  • Jaundice (yellow skin and eyes)

  • Difficulty breathing

  • Anemia

  • Irregular heart rhythms

In rare cases, an enlarged spleen can rupture. The spleen is a small organ near the stomach. Untreated, a ruptured spleen can cause life-threatening internal bleeding.

Page 2 of 9     Next Page:  Infectious Mononucleosis Diagnosis
Click here to to redeem your SparkPoints
  You will earn 5 SparkPoints
From Health A-Z, Harvard Health Publications. Copyright 2007 by the President and Fellows of Harvard College. All rights reserved. Written permission is required to reproduce, in any manner, in whole or in part, the material contained herein. To make a reprint request, contact Harvard Health Publications. Used with permission of StayWell.

You can find more great health information on the Harvard Health Publications website.