SAN FRANCISCO, Calif. (KRON) – The COVID vaccine is causing some women to think they have breast cancer.

This is according to a UCSF doctor who has seen a number of patients in the past few weeks with swollen lymph nodes.

“I really want women to hear, don’t panic at all,” Dr. Laura Esserman, director of the Carol Franc Buck Breast Care Center at UCSF and a breast cancer surgeon, said. 

Dr. Laura Esserman says she is seeing patients every day, who just got the COVID vaccine, who are concerned about swollen lymph nodes under their armpits and near the collarbone.

She says she saw three patients on Wednesday with this concern. Wendy Tice-Wallner was one of them.

“I have had a COVID shot since I saw you last and I’m not sure what that means in terms of evaluating my nodes any further and she said we won’t do that it might raise false concerns that you don’t need to have,” a patient Wendy Tice-Wallner said.

Swollen lymph nodes are typically a warning sign but for women who have recently gotten the COVID vaccine, these bumps are typically not cancers. They’re swollen glands, a common side effect of the vaccine that is just proving that the shot is doing its job.

“Every woman should know that when you get a vaccine that one of the things that happen is that you’re getting your immune system to rev up and start making antibodies and the factories for making those antibodies are your lymph nodes,” Dr. Laura Esserman said. 

The enlarged lymph nodes are showing up on mammograms like this one and are on the same side where women are getting vaccinated.

“This is being noticed incidentally on screening studies,” Bonnie N. Joe, MD, Ph.D., Chief of UCSF Breast Imaging, said.

Dr. Bonnie Joe, the chief of Breast Imaging at UCSF, recommends getting your mammogram before your vaccine or waiting four to six weeks after getting your vaccine to get your mammogram.

“The good news is that this is a natural reaction to the vaccine so most of the time these are going to resolve on their own,” Dr. Joe said. 

“The key thing there is to not panic and not to assume that that is a cancer,” Dr. Esserman said.