Colloquially referred to as the kissing disease, mononucleosis is a viral infection usually transmitted via saliva. The Epstein-Bar virus (EBV) is the most common cause of mononucleosis. Most healthy adults build up an immunity to the virus by the age of 40. Because of this, incidences of mononucleosis are highest among teenagers and young children. There is no cure for or vaccination against infectious mononucleosis. Treatment, thus, primarily aims to alleviate symptoms, which can range from mild to severe.

Malaise, Fatigue, and Weakness

The incubation period for mononucleosis is rather long, about four to six weeks in most people. The earliest sign of infection is malaise, a general feeling of ill-health. Many patients complain of fatigue and weakness in the days leading up to the appearance of other symptoms. These initial symptoms occur as a consequence of the virus gaining potency within the body.


Fever and Chills

The most common symptom of mononucleosis is a fever, typically accompanied by chills. The fever usually ranges from 100 to 102 degrees Fahrenheit, though it may recede in the last few days of infection. The fever usually lasts for 10 to 14 days, and chills persist only as long as the temperature is high. Over-the-counter medication can help to keep the fever in check, but you should always check with your doctor before self-medicating.


A Sore Throat

A sore throat is another symptom that frequently occurs in patients with mononucleosis. It can be quite severe during the three to five days when the infection is at its peak. As the infection subsides, the throat heals as well, though mild discomfort may continue for a week or more. Painkillers usually do not provide much relief, but a doctor may prescribe specific medication if the pain and itchiness become unbearable.


Swollen Lymph Nodes

Many people with mononucleosis observe swelling of the lymph nodes. They typically see this swelling in the posterior cervical lymph nodes at the back and neck. An infected person may also experience swollen armpits. In rare cases, swelling can develop in other areas with lymph nodes, such as the groin. Though the swelling generally doesn't last for more than a week, in rare cases mild swelling may remain for up to a month after the infection subsides.


Swollen Tonsils

Swelling of the tonsils can accompany a sore throat. In extreme situations, the tonsils may fill with pus, which is cause for medical attention. Petechiae or reddish-purple spots may appear on the roof of the mouth, as well. In many cases, these symptoms can be mistaken for strep throat, which produces similar effects, but a simple strep test can rule out this alternate infection.


Skin Rash

In some cases, mononucleosis causes a skin rash similar to measles, typically on the arms and trunk. Because mononucleosis comes from a virus, antibiotics are ineffective. However, a doctor may prescribe antibiotics if the sore throat if he mistakes the condition for a bacterial infection like strep throat. These antibiotics can sometimes produce a generalized itch or rash, though it is usually mild.


Spleen or Liver Enlargement

In rare cases, severe infection coupled with lowered immunity can lead to enlargement and inflammation of the spleen or liver. Symptoms include abdominal pain, loss of appetite, nausea, vomiting, and swelling of the lymph nodes in the groin area. If the spleen becomes enlarged, it is important to avoid contact sports or lifting weights for a few weeks to avoid rupturing the organ, a potentially life-threatening complication.



Jaundice leads to yellowing of the whites of the eyes, paleness or yellowing of the skin, and other, more subtle, symptoms. This is an indicator that the viral infection has impacted liver function, and called for immediate consultation and treatment from a physician.


Head and Body Aches

When the body is battling a viral infection, numerous vitamin and mineral deficiencies can occur, which can lead to physical aches. Fever and inflammation further promote headaches and body pain. Persistent headaches and pain in the limbs, back, and joints are common. Over-the-counter medication can provide relief from these symptoms, but infected individuals should always speak to a doctor about possible adverse medication interactions.


Difficulty Breathing

While the infection is in full force, a person with mono may experience breathing problems, especially when lying down or sleeping. In most cases, this is caused by narrowing of the nasal passages due to swelling of the pharynx or tonsils. This is another symptom of mononucleosis that calls for medical attention if it worsens.


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