How is Mono Diagnosed? Understanding the Tests for Infectious Mononucleosis
Published: Jan 31, 2024
Diagnosing infectious mononucleosis, or 'mono', isn't always straightforward. While some symptoms are telltale signs, doctors often need to run specific tests to confirm the diagnosis and rule out other conditions.
Contents
The Initial Suspect: Symptoms and Physical Exam
Doctors first look for classic mono symptoms like fever, sore throat, and swollen lymph nodes. They may also check for an enlarged spleen. However, these symptoms can mimic other infections, so further testing is usually needed for a definitive diagnosis.
Blood Tests: The Detective Work
Blood tests are crucial in diagnosing mono. A complete blood count (CBC) often shows an increased number of white blood cells, particularly 'atypical lymphocytes'. Liver function tests may also be elevated. The most specific test is for Epstein-Barr virus (EBV) antibodies, which can confirm recent infection.

The Monospot Test: Quick but Not Perfect
The 'Monospot' test is a rapid blood test that looks for heterophile antibodies produced in response to EBV. It's quick and widely available, but can miss some cases, especially in young children or early in the infection. False positives can also occur with other conditions.
Frequently Asked Questions
It's about 70-90% accurate in teens and adults.
Not always; your doctor will decide based on your symptoms.
Monospot results are quick; other tests may take a few days.
Yes, which is why throat cultures are sometimes done.
Key Takeaways
While mono diagnosis involves several tests, it's crucial for proper treatment and avoiding complications.
Wondering if you need mono testing? Chat with Doctronic to discuss your symptoms and get guidance on next steps.Related Articles
References
Ebell MH. Epstein-Barr virus infectious mononucleosis. Am Fam Physician 2004; 70:1279.
Hurt C, Tammaro D. Diagnostic evaluation of mononucleosis-like illnesses. Am J Med 2007; 120:911.e1.
Always discuss health information with your healthcare provider.