Both bullies and their victims take more trips to the nurse's office than other students - but not just for the obvious reasons.
In a new study published today in Pediatrics, kids involved in bullying were more likely to see the school nurse for illnesses and non-medical symptoms, in addition to injuries.
The finding means that school nurses could be the front line for spotting cases of bullying and bringing them to a stop.
Enlisting school nurses could be "another way of trying to keep a gauge of what's happening among the students in school," Eric Vernberg of the University of Kansas in Lawrence, the study's lead author, told Reuters Health.
"A lot of times, kids may experience some conflict, some bullying, and not involve the teacher or not tell a parent or not tell anybody really," he said, "particularly for a kid that's embarrassed about the difficulty they're having or afraid that saying things about it is going to make it worse in some way."
Recently, evidence has been piling up that being bullied can take a psychological toll on kids -- both during the bullying and later, when they are adults.
And some fear that bullying is becoming more common, with the internet providing a new and potentially anonymous outlet for harassment.
A week ago, two 8th grade girls from Minnesota, Haylee Fentress and Paige Moravetz, were found hanged in what their parents believed were suicides related to bullying the girls faced.
To take a closer look at one effect of bullying in elementary schools, Vernberg and his colleagues followed a group of almost 600 students in grades 3 through 5 at six schools for a year.
In the fall, every kid filled out questionnaires about how often they were bullied -- which included everything from being the target of rumors to getting hit or kicked -- as well as who the aggressive kids were in their class.
At the end of the year, the researchers collected logs from the school nurses and determined how often each kid went to the nurse and the reason for those visits.
On average, kids went to the nurse between four and five times each year.
Bullied kids and those identified as bullies by their peers had more visits to the nurse than other students for an illness, injury, or for complaints that didn't have a clear medical cause, such as stomach aches.
The researchers noted that boys and girls as well as kids of different races were just as likely to be bullied, but that boys and African-American kids were more likely to be labeled as aggressors than other students.
Sometimes, the link between bullying and a nurse's visit may be clear -- such as when a kid gets injured in a fight related to bullying.
In other cases, it might not be as obvious. Vernberg pointed to evidence that the long-term psychological stress brought on by bullying could compromise kids' immune systems and make them vulnerable to sickness.
And some bullied kids might just be looking for an escape from the hallways or playground and seek refuge with the school nurse, the researchers note.
Bullies themselves may also be targets of aggression or shunned by their peers.
"When you're a bully at elementary school you're more likely to be excluded from playground games. (Other kids) don't want to be friends with you," Dr. Tom Tarshis, the medical director of the Bay Area Children's Association in Cupertino, California, told Reuters Health.
Especially at a young age, "a lot of bullies have the same mental health problems as the victims do," said Tarshis, who has studied bullying but was not involved in the current research.
Keeping track of nurse's visits is one way that schools can keep an eye out for who might be involved in bullying, Vernberg said. But it's only one piece of the picture.
"The schools need to step up and be the most important component in any intervention. It can't just be going in the classroom and giving a couple talks," Tarshis said.
"We have to make sure the teachers are on board, the parents, the administrators, and the whole community."