Infectious mononucleosis, commonly known as “mono,” is a viral infection that frequently affects teenagers and young adults. A distinguishing feature of this illness is swollen lymph nodes, alongside symptoms such as fatigue, fever, and a sore throat. While the acute phase of mono typically resolves, many individuals wonder if these swollen lymph nodes can persist long after other symptoms subside.
Lymph Nodes and Mononucleosis
Lymph nodes are small, bean-shaped structures within the body’s lymphatic system, which supports immune function. Distributed throughout the body, including the neck, armpits, and groin, they filter lymph fluid, trapping foreign particles like viruses and bacteria. These nodes contain immune cells, such as lymphocytes, that identify and neutralize pathogens. When the body encounters an infection like mononucleosis, typically caused by the Epstein-Barr virus (EBV), lymph nodes become active. Immune cells within the nodes multiply rapidly to fight the virus, leading to increased size and often tenderness, a swelling known as lymphadenopathy that results from the immune system’s response to EBV.
How Long Lymph Nodes Can Remain Swollen
Lymph nodes often remain enlarged for an extended period even after primary mononucleosis symptoms, like fever and sore throat, have resolved. While many mono symptoms subside within two to four weeks, swollen glands can persist for several weeks to a few months, sometimes up to six months or longer. This prolonged swelling occurs because the body’s immune system continues to process viral remnants and address residual inflammation. The Epstein-Barr virus establishes a dormant presence in blood cells and lymph nodes, contributing to ongoing immune activity. The gradual reduction in lymph node size is a normal part of recovery as the immune response winds down.
Reasons for Persistent Swelling
Several factors can contribute to prolonged lymph node swelling. One reason is the body’s continued low-level immune activity as it eliminates the Epstein-Barr virus, even after the acute infection passes. Individual variations in immune response and healing times also play a role; some people naturally take longer to recover from viral infections. During recovery, the body might also be more susceptible to other mild infections. A new, minor infection could trigger renewed lymph node activity, causing existing swelling to persist or increase temporarily. Factors such as prolonged fatigue or stress can also impact overall recovery, influencing how quickly lymph node swelling resolves.
When to Consult a Doctor
While persistent lymph node swelling after mononucleosis is often normal, certain signs warrant medical evaluation. Consult a healthcare provider if the swollen lymph nodes continue to grow larger instead of decreasing, or if they feel very hard, are fixed in place, or have an irregular shape. Seek medical attention if swelling is accompanied by new or worsening symptoms, such as unexplained weight loss, night sweats, or a persistent fever. If the swollen lymph nodes become significantly painful or tender without clear reason, or if swelling lasts beyond three to six months, consult a doctor. These signs could indicate a different underlying issue requiring diagnosis and treatment.