Symptoms of Mononucleosis

Mononucleosis produces flulike symptoms.

  • Severe fatigue
  • Fever and chills
  • Sore throat, sometimes severe
  • Swollen glands (usually a day or two after the symptoms listed above) and enlarged spleen (in about 50 percent of cases)
  • Nausea and vomiting (occasionally)
  • Jaundice (in about 5 percent of cases)
  • Measles-like rash on the face or body (in about 15 percent of cases)—if amoxicillin, an antibiotic, has been taken, rash occurs in 90 percent of cases.

What Is Mononucleosis?

Often referred to as mono, mononucleosis is an infectious disease with initial symptoms—fever, sore throat, and swollen glands—that feel like a bad case of the flu (influenza). The condition is most common in teenagers and young adults in developed countries. (When it strikes young children, it is so mild that it usually goes unnoticed.) Over half of all college students have antibodies to the virus that causes mono, which means they have been infected with the virus previously.

Because mononucleosis may affect the liver, some people with the disease develop jaundice, a yellowing of the skin caused by an increase of bile in the blood. A skin rash similar to German measles (rubella) can also develop, and the rash can be aggravated if a physician prescribes amoxicillin—an antibiotic often used to treat severe bacterial infections of the throat—before mono has been diagnosed.

Mono is usually not a serious condition, and most people who come down with it generally feel better within several weeks. The sensation of fatigue can sometimes persist for two months or longer, which has in the past led some experts to think that the virus that causes mono is also linked to chronic fatigue syndrome. But research has shown no such link.

Major complications from mono are rare. About half of all mono patients get an enlarged spleen, and one of the most potentially serious complications is for the spleen to rupture—a rare circumstance that requires emergency surgery.

What Causes Mononucleosis?

The Epstein-Barr virus, a common member of the herpes family of viruses, is the cause of most cases of mononucleosis. The virus is communicable, but only through direct contact with the saliva of an infected person, which can occur through sneezing, coughing, and—perhaps most commonly—kissing. (Mono has been referred to as the kissing disease.)

The virus remains active in an infected person’s saliva for six months or more after symptoms have subsided. Some people, however, are able to come in contact with an infected person and not get sick, presumably because their immune systems are able to resist the virus.

What if You Do Nothing about Mononucleosis?

Mono is self-limiting; most people will recover on their own, typically in two to four weeks, though fatigue may last longer.

Home Remedies for Mononucleosis

There is no current treatment for the virus that causes mononucleosis, but you can take these steps to relieve symptoms.

  • Try to rest. Resting yourself physically is helpful during the acute, feverish phase of the illness. If you have an enlarged spleen, you need to be especially careful about resuming physical activity until your spleen has returned to normal; otherwise, you risk rupturing it.
  • Drink plenty of fluids. Even if a sore throat makes it uncomfortable to swallow, help yourself to ample amounts of water and fruit juices, especially while you have a fever.
  • Take nonprescription pain relievers. To relieve headache, sore throat, and fever, you can use an NSAID (aspirin, ibuprofen, or naproxen) or acetaminophen. Children 19 or younger should avoid aspirin, which carries a risk of Reye’s syndrome when taken by children with flu or chicken pox (and symptoms of mono are similar to flu symptoms). Instead, take acetaminophen or ibuprofen (though the latter won’t reduce fever).
  • Ease up on work and activity. Along with resting, it’s helpful to postpone difficult projects (such as lengthy papers or final exams if you are a college student) until after you’ve recovered.

Prevention of Mononucleosis

Mono can’t be prevented. Nearly all adults over 35 have antibodies to the virus, so they aren’t at risk. You can reduce the risk by avoiding direct contact with people known to be infected, but the virus can be carried in saliva long after symptoms have disappeared.

When to Call Your Doctor

It’s best to check with your doctor if you develop symptoms of mono, particularly if you have a severe sore throat; your doctor can rule out other possible infections, including hepatitis and strep throat, which call for different treatment measures. Also contact your doctor if you develop severe abdominal pain, which may indicate a ruptured spleen. And call your doctor if symptoms from mono last longer than 10 days.

What Your Doctor Will Do

After checking for signs and symptoms of mono (including an enlarged spleen), your doctor can confirm a diagnosis with blood tests for the Epstein-Barr virus.

For More Information about Mononucleosis

  • Centers for Disease Control and Prevention


The Complete Home Wellness Handbook

John Edward Swartzberg, M.D., F.A.C.P., Sheldon Margen, M.D., and the editors of the UC Berkeley Wellness Letter

Updated by Remedy Health Media

Publication Review By: the Editorial Staff at

Published: 11 Aug 2010

Last Modified: 28 Jan 2015