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Understanding Mononucleosis - Symptoms
What Are the Symptoms of Mononucleosis?
The early symptoms of mononucleosis resemble those of the flu, including:
- Severe fatigue.
- Headache.
- Sore throat, which sometimes can be very severe.
- Chills, followed by a fever.
- Muscle aches.
After a day or two, these additional symptoms may occur:
- Swollen lymph nodes.
- Jaundice (a yellow tinge to the skin and eyes).
- A measles-like skin rash anywhere on the face or body; sometimes the rash develops suddenly after taking amoxicillin for a severe sore throat.
- Tiny red spots or bruise-like areas inside the mouth, especially on the roof of the mouth (palate).
- Soreness in the upper-left abdomen, from an enlarged spleen.
Call Your Doctor If:
- You have been experiencing mono symptoms -- especially for longer than 10 days -- or you have a severe sore throat for more than a day or two. You need to be examined by a doctor to rule out other illnesses, such as strep throat or -- less likely -- leukemia or infectious hepatitis.
- You develop swollen lymph nodes all over your body, which may be a sign of tuberculosis, cancer, or HIV (human immunodeficiency virus).
- You develop abdominal pain, which may indicate a ruptured spleen. Seek emergency medical treatment immediately.
- You have both a rash and headache occuring together, which might be signs of meningitis.
- You develop a rash consisting of many tiny red spots (called petechiae), which could be a sign of a low platelet count or other serious illness such as meningitis.
WebMD Medical Reference
Reviewed by
Daniel Perlman, MD on July 02, 2007
© 2005 WebMD, Inc. All rights reserved.




