Not everyone infected with the virus that
mono (Epstein-Barr virus, or EBV) has symptoms. This
is especially true for young children, who may have a fever but no other
symptoms. People ages 15 to 24 are most likely to have obvious
most common symptoms of mono are:
- Fever, which may range from
101 °F (38.3 °C) to
104 °F (40 °C), and
- Sore throat, often with white patches on the tonsils (which
may look like
lymph nodes all over the body, especially the
lymph nodes in the neck .
- Swollen tonsils.
- Headache or
- Fatigue and a lack of energy.
- Loss of
- Pain in the upper left part of the abdomen, which may
mean that the
spleen has become enlarged.
These symptoms usually get better in about 1 or 2
You can get a rash if you take
the antibiotics amoxicillin or ampicillin when you have mono. These antibiotics are often prescribed for other causes of sore
throat, such as strep throat, and might be prescribed for you before the doctor
knows you have mono. The rash is not an allergic reaction.2
Mono may cause your
spleen to swell to 2 or 3 times its normal size. An
enlarged spleen occurs in up to 75 out of 100 people who have mono.3 A blow to the abdomen can cause an enlarged spleen to
rupture. To reduce this risk, avoid heavy lifting and contact sports for several
weeks after you become ill with mono or until your doctor says it is safe. In
very rare cases, the spleen may rupture on its own.
of mono can be more severe and last longer in people who have an
impaired immune system or a rare genetic condition
called X-linked lymphoproliferative syndrome.
The symptoms of
infectious mononucleosis, such as a sore throat and fever, also are
found in many other conditions.