Infectious Mononucleosis
What is Infectious Mononucleosis?
Infectious mononucleosis is a viral infection that people often call mono or the kissing disease. It spreads through saliva and causes extreme fatigue, fever, and swollen glands. The Epstein-Barr virus causes most cases of mono, though other viruses can trigger similar symptoms.
Mono affects teenagers and young adults most often, though anyone can catch it. The infection makes your body produce extra white blood cells to fight the virus. Your spleen may swell as your immune system works overtime. Most people recover fully within 2 to 4 weeks, but fatigue can last for months in some cases.
Blood tests can detect changes in your body that suggest mono infection. Your doctor looks for specific antibodies and elevated liver enzymes. Early detection helps you rest properly and avoid complications like a ruptured spleen.
Symptoms
- Extreme fatigue that lasts for weeks
- High fever, often reaching 102 to 104 degrees
- Severe sore throat with white patches
- Swollen lymph nodes in neck and armpits
- Swollen tonsils that make swallowing difficult
- Enlarged spleen causing left-side belly pain
- Headache and body aches
- Skin rash, especially after taking antibiotics
- Loss of appetite and nausea
- Night sweats
Some people have mild symptoms that feel like a regular cold. Young children often show fewer symptoms than teens and adults. The fatigue typically appears first and lasts the longest.
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Causes and risk factors
The Epstein-Barr virus causes about 90% of mono cases. This virus spreads through saliva when you share drinks, kiss someone, or use the same utensils. You can also catch it from coughing or sneezing. The virus has an incubation period of 4 to 6 weeks, meaning symptoms appear long after exposure.
People with weakened immune systems face higher risk of infection. Stress, lack of sleep, and poor nutrition make it easier for the virus to take hold. Teenagers and college students catch mono frequently because they live in close quarters and share food and drinks. Once infected, the virus stays in your body forever but usually remains inactive after recovery.
How it's diagnosed
Doctors diagnose mono through physical exams and blood tests. Your doctor will check for swollen lymph nodes, enlarged spleen, and throat inflammation. Blood tests show elevated white blood cells and specific antibodies that fight the Epstein-Barr virus.
Rite Aid offers blood testing that measures LD and Rheumatoid Factor. Elevated LD levels often appear during mono because the virus breaks down cells throughout your body. Rheumatoid Factor may show false-positive results during mono infection. Testing at Quest Diagnostics locations helps track your recovery and rule out other conditions with similar symptoms.
Treatment options
- Rest as much as possible for at least 2 to 4 weeks
- Drink plenty of water to prevent dehydration
- Take over-the-counter pain relievers for fever and sore throat
- Gargle with salt water to soothe throat pain
- Avoid contact sports for 4 to 6 weeks to prevent spleen rupture
- Eat soft foods if swallowing becomes too painful
- Avoid alcohol to protect your liver during recovery
- Use a humidifier to ease breathing and throat discomfort
Antibiotics do not work against mono because it comes from a virus, not bacteria. Doctors rarely prescribe antiviral medications unless complications develop. Most treatment focuses on managing symptoms while your immune system fights the infection. See a doctor immediately if you have sharp belly pain, which may signal a ruptured spleen.
Concerned about Infectious Mononucleosis? Get tested at Rite Aid.
- Simple blood draw at your nearest lab
- Results in days, not weeks
- Share results with your doctor
Frequently asked questions
Most people recover from mono within 2 to 4 weeks. Fatigue often persists for several months after other symptoms disappear. You remain contagious for several weeks even after feeling better. Rest and proper hydration speed up recovery time.
Getting mono twice is extremely rare but possible. The Epstein-Barr virus stays dormant in your body after infection. Your immune system usually keeps it inactive for life. People with weakened immunity may experience reactivation of symptoms.
Mono causes extreme fatigue that lasts weeks, while strep throat does not. Strep throat responds to antibiotics, but mono does not. Both cause sore throat and fever, making blood tests important for accurate diagnosis. Mono often includes an enlarged spleen, which strep throat never causes.
See a doctor if you have extreme fatigue with fever and sore throat lasting more than a week. Sharp pain in your upper left belly requires immediate medical attention. Difficulty breathing or swallowing also needs urgent care. Blood tests confirm the diagnosis and rule out other serious conditions.
Complications are rare but can include a ruptured spleen, liver inflammation, and anemia. Your spleen can rupture if hit during contact sports or rough activity. Some people develop heart or nervous system problems. Most people recover fully without lasting effects if they rest properly.
Blood tests measure LD levels, which rise when the virus breaks down cells. Doctors also check for Epstein-Barr virus antibodies and elevated white blood cells. Rheumatoid Factor may show false-positive results during active infection. Complete blood counts reveal how your immune system responds to the virus.
Your immune system uses enormous energy fighting the Epstein-Barr virus. The virus infects white blood cells and forces your body to produce more. Your liver and spleen work overtime filtering damaged cells. This full-body immune response drains your energy for weeks or months.
You can reduce your risk by not sharing drinks, food, or utensils with others. Avoid kissing people who have active symptoms. Wash your hands frequently, especially before eating. No vaccine exists for mono, so avoiding saliva contact remains the best prevention.
Yes, you can spread mono during the 4 to 6 week incubation period. You remain contagious for several weeks after symptoms start. Some people continue shedding the virus in their saliva for months. This long contagious period makes prevention challenging.
Mono often enlarges your spleen, making it fragile and prone to rupture. A blow to your belly during sports can tear the spleen, causing life-threatening internal bleeding. Doctors recommend avoiding contact sports for at least 4 weeks. Your doctor should check that your spleen has returned to normal size before you resume activities.