Nevertheless, “Enlarged lymph nodes after the COVID vaccine are a normal response of the body,” says Dr. Desperito, who is also an assistant professor of radiology at Columbia University Vagelos College of Physicians and Surgeons. “They will enlarge temporarily and return to their normal size after several weeks.”
Lymph nodes, small beanlike structures throughout the body, are an essential part of the immune system. “They contain lymphocytes, or white blood cells, which help fight infection and disease,” says Dr. Desperito.
The nodes tend to swell when they are reacting to a bacterial or viral infection. Because COVID-19 vaccines prompt an immune response, they can cause a similar reaction. The swollen glands typically appear on the side of the body where the vaccine was administered, such as the left armpit nodes in patients who have gotten the shot in their left arm.
It’s not uncommon for vaccines to cause swollen lymph nodes after vaccinations. This has occurred after other immunizations, such as the H1N1 influenza vaccine. “But with COVID, it’s happening on such a large scale that more people have experienced the reaction and a public conversation is needed,” says Dr. Desperito.
How can you make sure your cancer screenings don’t lead to an unnecessary cancer scare or tests? “Talking to your healthcare provider is the first, most important step,” says Dr. Desperito. She suggests the following measures: