Infectious Mononucleosis

If you have been diagnosed with mono, seek care immediately if:

• You have severe pain in the upper left part of your abdomen. This may indicate that your spleen has ruptured. Rupture of an enlarged spleen caused by mono is rare. It is most likely to happen because of a blow to the abdomen, but it may sometimes happen even without such an injury.⁵
• Your tonsils become so swollen that you find it difficult to breathe or swallow.

If you have not been diagnosed with mono and you have a severe sore throat that has lasted longer than 2 to 3 days after trying home treatment, call your health professional within 1 to 2 days.

If you have not been diagnosed with mono and have tried home treatment for 7 to 10 days, contact your doctor if you have:

• A lack of energy.
• Body aches.
• Swollen glands.

Watchful Waiting

Most cases of mono do not require treatment, but you still need to take care of yourself until the illness goes away. You should see your doctor to make sure your symptoms are not caused by a treatable infection, such as strep throat. If it is certain you have mono:

• Get plenty of rest.
• Gargle with salt water or use throat lozenges to soothe your throat.
• Take nonprescription pain relievers to reduce fever and relieve a sore throat and headaches.
• Avoid contact sports and heavy lifting for 4 weeks after you become ill with mono (or until a doctor tells you it is okay). Mono can cause your spleen to enlarge, and these activities can increase your risk for injuring your spleen.

Who To See

The following health professionals can diagnose and treat mono:

• Family medicine doctor
• Pediatrician
• Internist
• Physician assistant
• Nurse practitioner

To prepare for your appointment, see the topic Making the Most of Your Appointment.