The next time you call in sick, your boss could be ready to call your bluff.

That’s because almost half of us are claiming to be under the weather when we’re really right as rain, according to a new CareerBuilder survey released Thursday.

Forty percent of employees admitted to calling in sick during the past 12 months when they were perfectly healthy, compared to 35% of workers who played hooky last year.

But liar beware: Thirty-eight percent of employers checked up on an ailing worker, and 1 in 4 (26%) have fired someone that they found using a phony excuse.

So how did those fakers get caught? Oversharing, of course. CareerBuilder reported that 43% of employers found an employee was fibbing about being sick after clicking through their social media posts – and that’s up from 34% last year.

The sick thing is, 28% of workers who have paid time off — which means they could take a vacation day or a personal day if they need a break — still felt the need to “make up” an excuse (like having a stomach bug) for taking the day off. The most common reasons for skipping out included having a doctor’s appointment (30%), didn’t feel like working (23%), needing to relax (20%) and catching up on sleep (15%).

And more than a third of workers told CareerBuilder that they came into the office sick instead of recuperating at home because they wanted to save their sick days for when they’re feeling well.

Illness does sometimes really get the best of us all. Drake was forced to cancel a concert earlier this year after a bad sushi roll gave him food poisoning — a move that was greeted with a storm of middle fingers and thrown sodas from an audience that had been waiting over 75 minutes, according to Hollywood life. Sickness also forced Amy Schumer to cancel several shows in Canada, angering some fans. 

Most of us, of course, emerge from a sick day without a slew of venom spat at us on Twitter, but with other worries. Almost a quarter of U.S. adults have lost a job, or been threatened with job loss, for taking too much sick leave. And the pressure is clearly on: 26% of U.S. workers have gone to work while they were sick, according to a survey by the National Science Foundation.

If you’re thinking about taking a sick day, first figure out whether you should call out. Bottom line: If you’re too sick to come in, stay home. Period. While it may seem like powering through a work day while sick is necessary, it could hurt your career in the long run. “When we just push through, we often end up needing more time off, because we end up getting more sick than if we had just taken a day off to rest and recover,” says Katie Bennett, career coach and co-founder of Ama la Vida coaching.

Next, ask yourself whether you’re well enough to be an asset to your team, said Bennett. If not, stay home. “And even if you’re nearly over a cold, but coughing and sneezing and giving the appearance that you’re ill to others, it might be best not to go in, just so people don’t go ‘Should you even be here?’” said Bruce Cameron, counselor and executive career coach from Dallas.

Ready to call in sick? Here’s how to do it.

1. Call early. If you can, call the day before, says Tim Toterhi, founder and executive coach of Plotline Leadership. If you wake up sick, call as soon as you can–the sooner your boss knows you’re not coming, the more time they have to inform your colleagues and find coverage for your duties. Your boss may have a form of communication they prefer. If you’re not sure, “call and leave a message, and then follow up with an email.”

2. Be honest. Your explanation should be detailed and, above all, truthful. According to a Careerbuilder.com study, 33% of employers have checked alternate sources to see if an employee was telling the truth after calling in sick. With afflictions like the flu or a virus, “protect yourself by getting documentation” from a doctor, advised Laura MacLeod, founder and CEO of From the Inside Out Project.

With less serious conditions, a clear, objective explanation will suffice–and finish with an apology. “Give a good solid description,” said Cameron. Such as, “I have a low-grade fever, and I don’t want to bring that into the office today.” Follow it with something like “I’m so sorry I couldn’t be there. I anticipate I’ll be back tomorrow.”

3. Arrange for your work to get done. Ask someone else to cover your work, says Bennett. “Reschedule your important meetings…Organize everything you can so all your boss really needs to know is that you’re not going to be at the office.” If you’re too contagious to go in, but you feel okay, consider offering to work remotely.

This story was originally published in June and has been updated.