Infectious mononucleosis, often called mono, is an infection mainly caused by the Epstein-Barr virus (EBV). While it can impact people of all ages, it’s most commonly found in teenagers and young adults. Mono spreads easily through saliva, which is why it’s sometimes referred to as the “kissing disease.”
People with mono generally experience symptoms like tiredness, fever, swollen lymph nodes, and a sore throat. To diagnose mono, doctors perform physical exams and blood tests. Treatment typically involves rest and pain relievers, although more serious cases might require medication. In the U.S., approximately 125,000 cases of mono are reported each year.
Mono symptoms don’t appear right away; they usually show up four to six weeks after being exposed to EBV. These symptoms can be mild or severe, and many young children who contract EBV might not exhibit any symptoms at all.
Once symptoms do develop, they often last 2 to 3 weeks, but fatigue can linger for months. Classic symptoms of mono are quite common, but there are also less common ones. EBV, a type of herpes virus, is responsible for about 90% of mono cases, though other viruses can cause it as well.
The virus spreads through close contact with someone else’s saliva or bodily fluids, like kissing or sharing utensils. When EBV enters the body, it infects and changes specific white blood cells known as B lymphocytes, causing them to multiply rapidly. The immune system then produces T lymphocytes and other cells to combat these infected B lymphocytes, which leads to mono symptoms.
By age 30, about 90% of people worldwide have EBV antibodies, indicating they’ve been infected at some stage. Once infected, the virus stays in the body forever, but it usually doesn’t lead to long-term issues for most people.
Not everyone exposed to EBV develops mono, but certain factors can make it more likely. Diagnosing mono requires a physical exam, a symptom review, and a blood test. During the exam, the healthcare provider will check your symptoms, their duration, and severity. They’ll feel your neck and throat for swollen lymph nodes and check your abdomen for an enlarged liver or spleen. Blood tests help confirm the diagnosis if mono is suspected. If necessary, a throat swab will rule out strep throat due to its similar symptoms.
Mono progresses through three stages, though not everyone experiences them all, and symptoms can appear at varying times. Treating mono focuses on easing symptoms and supporting your body’s own healing process while your immune system fights the virus. Common treatments include rest, hydration, and proper nutrition.
There isn’t a vaccine or surefire way to prevent mono since the virus spreads so easily through close contact. To avoid getting it, steer clear of kissing or being close to someone with mono until they get better. Good hygiene, like washing your hands often, and avoiding sharing items like glasses, utensils, or toothbrushes, can help minimize the risk.
Most people recover from mono without issues, but there are possible complications. Having mono can be draining, and it might prevent you from going to work or school, or participating in activities you enjoy. Thankfully, most recover within 2 to 6 weeks. The key to recovery is resting as much as you can and avoiding strenuous activities to give your body time to heal. Make sure to get plenty of sleep, stay hydrated, and eat a balanced diet to support your immune system. Due to the risk of a swollen spleen, avoid contact sports and heavy lifting for at least a month to prevent rupture. Consult a healthcare provider if your symptoms persist or if new ones develop, like jaundice, abdominal pain, difficulty swallowing, or severe headaches.
