You know the classic signs: You're dragging at work, you're yawning all day, you're sluggish and you swear you can actually hear your bed calling your name. You need to sleep.
On the days when a fourth cup of coffee is masking the most obvious signs, you might think you've won the battle. But don't kid yourself. There are some tell-tale, though surprising, signs that your body is craving shuteye, even if you might chalk them up to other factors.
In fact, about a third of American workers, or roughly 40.6 million adults, get fewer than six hours of sleep each night, HuffPost reported in April
Getting less than the optimal seven to nine hours recommended by the CDC can result in serious health issues, like heart problems and obesity. But it can also disturb your day-to-day behavior in some more subtle ways.
Click through the slideshow below for some of the more surprising signs you need to sleep. Then tell us in the comments which ones you've noticed.
For more on sleep, click here.
Flickr photo by ohmeaghan