A soreness in the throat. This isn’t the simple soreness that one associate with the common cold – that caused by infectious mononucleosis is extremely intense. Ingesting anything can become difficult, or all-but-impossible, including the swallowing of one’s own spittle. The defining factor that sets soreness of the throat that is caused by mononucleosis apart from that caused by a cold, is that the other common symptoms of a cold will be absent. You will not sneeze, or have a cough, or experience a running nose.
Exhaustion. Exhaustion is a symptom of mononucleosis, just as it is of a great many ailments. You may feel as you do when you have the flu. You will want to stay in bed for as long as the illness persists. If you feel persistent exhaustion, you should know that this is generally a symptom of illness, and you should dig deeper to seek the cause.
Running a temperature. If you have been running a temperature, there is a good chance that you are suffering from some sort of serious infection. While a great many infections, besides mononucleosis (also called the kissing disease), can cause a rise in temperature, any fever that persists over a 10-day period may be considered serious.