If you’re always the first to volunteer and the last to leave, you might be heading for a “competence hangover.” That’s at least according to Peter Duris, CEO and co-founder of career platform Kickresume, who is sounding the alarm on the burnout that hits when you’re so good at your job that everyone relies on you for everything.

“Wanting to make sure everything gets done to a high standard is great, but it can also take a toll over time, leading to unnecessary stress,” Duris warns. “If you frequently go above and beyond at work, it could result in a competence hangover—the type of burnout you can get when you feel inherently responsible for keeping things afloat.”

In other words, the better you are at your job, the harder it becomes to stop doing it.

Duris would know: his platform has helped more than 8 million people get hired at companies including Google, Apple, and Microsoft, giving him a front-row seat to the habits and hang-ups of high performers worldwide. And the data he’s seeing paints a troubling picture.

Kickresume’s own research found that 48% of Americans are experiencing imposter syndrome and overworking as a result. A third feels guilty taking time off. Nearly one in five feel pressured to keep working even when sick.