Clinical manifestations of this disease are quite complicated. At early stage, patients usually have fever, aversion to cold, body pains, cough, nasal obstruction, running nose, sore throat, neck struma. In late stage, patients may have symptoms such as irritability, flush face, dry mouth and lips, dry stool, yellow urine, touch pain, abdominal mass, vomit, fatigue, etc.

Symptoms of Infectious Mononucleosis in western medicine
Infectious Mononucleosis, also known as the "kissing disease," or simply "mono," is a group of symptoms that occur in some individuals who become infected with Epstein-Barr virus (EBV). The Epstein-Barr virus (EBV) is so widespread that 90% to 95% of all adults everywhere have signs of it in their blood. Infants become susceptible to EBV when they are no longer protected by their mother's immune system, usually after the first year of life. Fortunately, young children don't show symptoms when they are infected. Additionally, getting EBV infection at an early age confers lifetime immunity against future infections.

Teens and young adults ages 15 to 25 who escaped EBV infection during early childhood are at high risk of developing symptoms if they become infected with EBV. Mono is rare, but not totally unheard of in middle age. Almost all cases of mono resolve within a month. Most teens and young adults get well within two to three weeks with treatment no more complicated than drinking plenty of fluids and getting adequate bed rest. The older the infected person, the more severe the symptoms tend to be. These initial symptoms can last from one to three days before the more intense symptoms of the illness begin. The more common intense symptoms include:
1) Fever
2) Sore throat
3) Fatigue
4) Weakness
5) Swollen glands in your neck and armpits
6) Loss of appetite
7) Night sweats

What are the signs of mono?
1) a very reddened throat and tonsils,
2) swollen lymph nodes in the neck that typically occur on both sides.

The tonsils have a whitish coating in at least one-third of the cases. The spleen (sometimes referred to as the body's biggest lymph node) is an organ found in the left upper abdomen underneath the rib cage, which becomes enlarged or swollen in about half of patients with mono. An enlarged liver and abnormalities in liver function tests (blood tests) may be detected (see Complications, below). Some of patients have a splotchy red rash over the body, which has a similar appearance to the rash of measles. Early in the course of disease (over the first few days of illness), a temporary swelling (edema) of both upper eyelids may appear.