Swollen lymph nodes after COVID-19 vaccine mean it is working, doctor says

DETROIT (FOX 2) - Some people receiving a COVID-19 vaccine are reporting swollen lymph nodes, a side effect that is actually a good sign.

Dr. Laura Dean, with the Cleveland Clinic, said swollen lymph nodes are a sign that the vaccine is working. People who have experienced this side effect are typically noticed lymph nodes that are swollen on the underside of the arm that was vaccinated within 2-4 days of receiving the vaccine.

"We know that lymph node swelling can be a common reaction, or side effect, to any vaccine -- especially the flu vaccine or the shingles vaccine that we've had lots of experience with over the years," Dean said. "And that seems to be especially true following the COVID vaccine so that's drawn a lot of attention."

Dean said that the small number of people who have reported swollen lymph nodes usually have them return to normal within four weeks.

While swollen lymph nodes are a common vaccine reaction, they can be a sign of other problems, such as cancer, so Dean said to contact a healthcare provider if you are concerned.

"Your doctor may be able to reassure you. They may send you for imaging studies, such as an ultrasound of your lymph nodes up under your arm and then we can just kind of follow you and make sure that everything is responding as we would expect in a typical vaccine reaction."

If you have a routine mammogram scheduled around the time of your vaccination, Dean said to get it done but let your doctor know you have just received the vaccine.