And just as knowing your child is important in making your decisions, knowing what the disease is can be, as well, especially when trying to gauge if your child's illness is still contagious.
"You wouldn't want somebody else coming in and infecting your child," said Dr. Jon Abramson, chair of the pediatric department of Brenner Children's Hospital of Wake Forest University Baptist Medical Center.
One example he gives is strep throat, where a child can go back to school once they have been on antibiotics for 24 hours, because they are no longer contagious.
Parents should also have a few other questions in mind when they make their decision to send their child to school.
"Are there other children in the house who have just been through the same illness? Is there something going around that school that this fits?"
Abramson said that by spending some time thinking about it, parents may be able to make a more informed decision about how to handle their sick child.
Of course, sometimes the children are just trying to get out of school for a few days.
"Occasionally, we get admitted kids who supposedly had fever for a long period of time," said Abramson.
In these cases, he said he often asks if the parent is taking the temperature and if they stay in the room the whole time.
Years ago, he said, he recalls having one child where the parent would leave the room and the child would dash to the sink to run the thermometer under hot water.
Parents need to know, Abramson said, "What is the level of sophistication in the child?"
Other things he said to look out for are children who act better once they are told they don't have to go to school, as well as children who are sick frequently, but never ill on weekends.
He also said that the main thing is not to give children an incentive to stay home.
"Don't give gifts," said Abramson. "You don't want to incentivize them to stay home. Be sympathetic and make sure they're comfortable, but don't give them gifts."
Altmann also recommends restricting many activities, such as watching television or any trips to the park.
She said that when a child is sick, they may need an extra bit of TLC, but while that may mean that a parent reads them some extra stories, it will mean they can't do certain other things.
Altmann said parents have to let their children know that, "When we get better, then we get to go back to all the usual fun activities."
But on the flip side of the illness coin, parents should also watch out for children who may be sick but not tell their parents because they don't want to miss a certain activity.
Abramson notes that this may be common among student athletes who don't want to miss a game. In this case, parents may want to watch if their child is unusually sluggish or showing other signs of illness, even if they aren't complaining.
"You have to understand what their motivation is to make the decision," he said.
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