Mononucleosis, also called mono, is caused by infection with the Epstein-Barr Virus (EBV). EBV is a member of the herpes family of viruses and is so common that the Centers for Disease Control and Prevention (CDC) report that in the United States, 95 percent of those ages 35 to 40 have been infected. Often the viral infection goes unnoticed, but in adolescents and young adults the virus will result in infectious mononucleosis in about 35 to 50 percent of cases, according to the CDC. Because this virus is transmitted from person to person through intimate contact with infected saliva, mono is also known as "the kissing disease." Because there is no specific treatment to fight the virus, treatment aims to relieve symptoms.
Fever
Fever is a benchmark symptom of mononucleosis. A fever in an adult is technically any body temperature that measures 99 and higher, as specified by the National Institutes of Health.
The fever occurs as the body's immune system recognizes the virus as a foreign invader. The immune cells work to fight the virus, which increases the body's temperature. Because many viruses thrive at body temperature and cannot live at higher temperatures, the fever can help to kill the virus.
Sore Throat
A sore throat, also known as pharyngitis, is also a common symptom of mononucleosis. The sore throat will get progressively worse and can last anywhere from one to four weeks.
The presence of a sore throat along with the fever is often mistaken for strep throat, which is caused by a Streptococcus bacterial infection. A doctor can differentiate between the two illnesses by taking a culture of the throat to determine the presence of bacteria. When a bacterial culture comes back negative, the doctor may perform a mono-spot test, which tests for the presence of heterophile antibodies, antibodies produced when fighting mononucleosis.
Swollen Lymph Nodes
Patients with mononucleosis will have swollen lymph nodes in the throat and neck. Lymph nodes are small glands that are part of the immune system. They store white blood cells and act as filters to trap foreign and potentially dangerous invaders such as viruses and bacteria. When the body is fighting an infection, they can become swollen due to the increased number of white blood cells.
Fatigue
Those suffering from mononucleosis will often feel fatigue, or extreme tiredness. The body is fatigued because it is busy fighting the viral infection. The best way to recover from mononucleosis is to get plenty of rest so that your body can use its energy against the infection. Although the symptoms of mononucleosis usually subside in four to six weeks, the doctors at the Mayo Clinic advise not to return to normal activity levels too soon, as this could trigger a relapse of the infection.
