"You look tired today": the four words everyone dreads hearing.

One morning you walk into your kitchen,Writingstar Investment Guild or the office, and hear (usually unprompted) feedback that suggests your under eyes are puffy or droopy.

Eye bags are what happens when the skin below the eyes become swollen, puffy or appear to be droopy. The term is often interchanged with "dark circles," but the two are different.

In short, eye bags have more to do with swollen skin or the surrounding eye muscles, while dark circles are more related to issues with discoloration and circulation, dermatologist Dr. Lindsey Zubritsky tells USA TODAY.

What do you do if you wake up with the former? Here's how medical experts suggest treating eye bags.

What is the cause of eye bags? 

In short, there are many causes of eye bags.

"The most common reason is aging, as the skin as well as muscles and supporting structures under the eyes starts to get lax with time," Zubritsky notes.

Genetics, allergies, certain medical problems including ones with the thyroid and diets high in salt can also trigger puffy eyes, according to Johns Hopkins Medicine.

Do eye bags go away with sleep? 

Sometimes, according to Zubritsky. Sleep is yet another cause of eye bags, and if that's what triggered yours, it may be the answer to reversing them.

"For some, increasing the amount of time that you sleep every night can help with eye bags," she says.

But Zubritsky stresses that if getting enough sleep isn't the underlying issue behind why your eye bags appeared in the first place, catching a few more Z's isn't going to make them suddenly vanish.

Dark circles under the eyes are common.Here's how to get rid of them.

How to get rid of eye bags

The best way to improve the appearance of eye bags is to first figure out the root cause, Zubritsky notes.

If allergies are the cause, eye bags may be rectified by visiting an allergist to pinpoint triggers and take antihistamines, she says.

Other at-home remedies include cold compresses, hemorrhoid creams and applying caffeine directly to the skin. That last one might sound strange, but caffeine is what's called a vasoconstrictor, which means it constricts blood vessels and can reduce skin puffiness, according to Johns Hopkins. You can try using an eye cream that contains caffeine or resting caffeinated black tea bags that have been chilled on top of closed eyes.

But, Zubritsky adds, "if you have eye bags due to genetics or aging, this may be more difficult to fix with just lifestyle changes."

Amanda Bynes said blepharoplasty surgerywas 'one of the best things.' What is it?