Studies show sleep loss slows your reaction time — even if you think you're OK.

• And research suggests that the cognitive and motor impairments from lack of sleep can be similar to — or worse than — being drunk.

Sleep-deprived people "lose the ability to judge how well they're doing," Karin Johnson, a sleep medicine specialist and professor of neurology at UMass Chan School of Medicine-Baystate, told Axios.

• "You need sleep to make good judgment."

Yes, but: Some people can function perfectly well with six hours of sleep, Johnson said.

• On vacation, do you sleep in? If so, you're probably not getting enough sleep now.