When fatigue, a sore throat, a high fever, a headache or swollen lymph nodes in the neck don't seem to go away, you may have the most common symptoms of infectious mononucleosis, better known as mono.

Anyone who experiences these symptoms for weeks at a time should contact his or her family doctor. A blood test called mono spot is the most common way to diagnose mono, says Dr. Bradley Britigan, professor of internal medicine at the University of Iowa College of Medicine and a staff physician at UI Hospitals and Clinics.

"After diagnosis, little medical treatment is needed since 95 percent of patients with mono recover on their own," Britigan says. The best ways to recover from mono are to avoid participating in tiring physical activities and get lots of sleep, especially during the first two weeks of the disease.

Other common treatments include plenty of liquids and aspirin or acetaminophen. "Most treatment depends on each patient's specific symptoms," he adds. "For example, someone with a sore throat should gargle with salt water."

Recovery may take anywhere from two weeks to two months. Fevers and sore throats generally last one to two weeks, but fatigue may last up to a couple months. Hospitalization is uncommon, although it is not unusual for people to miss two or more weeks of school or work.

If a person has difficulty swallowing or breathing because of severely swollen lymph nodes or tonsils, or has other rare but dangerous complications of the disease, steroids may be prescribed, Britigan says. However, steroids can have negative side effects such as stomach ulcers, retention of fluids, or suppression of the immune system, so they aren't routinely prescribed for patients. Antibiotics are prescribed only if a secondary bacterial infection sets in.

Mono can also cause an enlarged spleen. "When this happens, people should avoid physical contact sports or anything that involves contact with the abdominal area," he says. Those with mono should also avoid drinking alcohol because it may aggravate the mild hepatitis--liver injury--which often accompanies mono.

Mono is caused by a virus called the Epstein-Barr virus (EBV) and is transferred through saliva. EBV causes lymphocytes--white blood cells that fight infections--to enlarge and increase in number. "You can acquire this virus at any age," Britigan notes. "Symptoms vary with your age. Many people acquire the virus as children. A person may have no symptoms whereas in some cases it may show up as a common cold or other brief viral infection." People who acquire the virus during childhood are carriers and can pass it on to others, even though they do not exhibit any symptoms of mono.

"If the virus is passed on to someone who was exposed to the virus during childhood, this person won't get mono," Britigan explains. However, if someone is exposed to the virus for the first time as a teenager or adult, he or she has the potential to develop mono.

Perhaps the best news about mono is that once you have it, you won't experience the disease again.