The illness comes on gradually with flu-like symptoms fever headache, and lethargy. After a few days some people notice swelling and painful areas in their neck. Gland swelling can also occur in the armpits and groin.
Most people develop a sore throat and fever.
Internally the spleen may enlarge causing the upper left abdomen to be tender. A virus found in saliva and other body fluids cause mono. It is diagnosed with a blood test. Many providers will also do a throat culture at the same time to rule out strep throat another separate illness with a different kind of treatment. Because mono is a virus there is no antibiotic treatment.