Health Topics A-Z

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, the following 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, particularly for longer than 10 days, or if 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 human immunodeficiency virus (see AIDS).
• You develop abdominal pain, which may indicate a ruptured spleen. Seek emergency medical treatment immediately.
• Rash and headache occur 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.

© 2005 WebMD Inc. All rights reserved.