Infectious mononucleosis (mono) is often called the kissing disease. The virus that causes mono is transmitted through saliva, so you can get it through kissing, but you can also be exposed through a cough or sneeze, or by sharing a glass or food utensils with someone who has mono. However, mononucleosis isn't as contagious as some infections, such as the common cold.

You're most likely to get mononucleosis with all the signs and symptoms if you're an adolescent or young adult. Young children usually have few symptoms, and the infection often goes unrecognized.

If you have mononucleosis, it's important to be careful of certain complications such as an enlarged spleen. Rest and adequate fluids are key to recovery.

Symptoms Causes Complications Prevention

Signs and symptoms of mononucleosis may include:

  • Fatigue
  • General feeling of unwellness (malaise)
  • Sore throat, perhaps a strep throat that doesn't get better with antibiotic use
  • Fever
  • Swollen lymph nodes in your neck and armpits
  • Swollen tonsils
  • Headache
  • Skin rash
  • Soft, swollen spleen

The virus has an incubation period of approximately four to six weeks, although in young children this period may be shorter. Signs and symptoms such as fever and sore throat usually lessen within a couple of weeks, although fatigue, enlarged lymph nodes and a swollen spleen may last for a few weeks longer.

When to see your doctor

If you've been experiencing the above symptoms, you may have mononucleosis.

If rest and a healthy diet don't ease your symptoms within a week or two or if your symptoms recur, see your doctor.

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