Lymph nodes are small, bean-shaped glands that are a key part of the body’s immune system. Understanding why lymph nodes swell can help alleviate worry and indicate when medical attention might be necessary.
How Lymph Nodes Work
Lymph nodes function as filters for foreign substances like viruses, bacteria, and other harmful materials. They are strategically located throughout the body, including the neck, armpits, and groin. These nodes contain specialized immune cells, including lymphocytes, which actively fight off infections and diseases.
When the body encounters an infection or illness, these immune cells multiply rapidly within the lymph nodes. This increase in cell count and the trapping of foreign particles cause the nodes to swell. This swelling, often with tenderness, signals an active immune response.
COVID-19 and Lymph Node Swelling
Lymph nodes can swell in response to a COVID-19 infection. This occurs as part of the body’s immune response to the SARS-CoV-2 virus, where the lymphatic system processes viral components and activates immune cells.
Swollen lymph nodes with COVID-19 are commonly observed in the neck region, as the virus often affects the upper respiratory tract. Swelling can also occur in the armpits or above the collarbone. This response typically manifests within a few days of infection and can persist for several weeks.
COVID-19 vaccination can also lead to temporary lymph node swelling, particularly in the armpit on the side where the shot was administered. This signals that the vaccine is successfully prompting an immune response and antibody production. While usually transient, this swelling can sometimes last for several weeks or even months.
Other Reasons for Swollen Lymph Nodes
Swollen lymph nodes are a common symptom of many conditions beyond COVID-19. They frequently enlarge due to common infections such as colds, the flu, strep throat, ear infections, skin infections, and mononucleosis. Other vaccinations, like the flu shot, can also trigger temporary lymph node enlargement near the injection site. Less common causes include autoimmune disorders like lupus or rheumatoid arthritis, and rarely, certain cancers.
When to Consult a Doctor
Most instances of swollen lymph nodes resolve as the underlying infection clears. However, certain signs warrant medical evaluation. Seek professional advice if the swelling persists for more than two to four weeks or continues to grow. It is also important to consult a doctor if the nodes feel hard, rubbery, or do not move freely when touched. Additional symptoms like unexplained weight loss, persistent fever, night sweats, or difficulty swallowing or breathing alongside swollen lymph nodes should prompt immediate medical attention.