Sinus

A nasal allergy or a chronic sinus condition can create bags under your eyes. According to thebeautybrains.com, when your under-eye area swells and then deflates and swells and deflates time and time again during a sinus infection, this can cause loose skin to develop, which will eventually turn into under-eye bags. In addition, when you cough, sneeze and hack from your allergies or sinus infection, this forces air to escape through your sinuses, which pushes air in behind the fat pockets under your eyes. The fat pockets then protrude. Get your sinus infection or allergies treated, which should reduce the under-eye bags.

Thyroid or Kidney Problems

According to Dr. Lawrence E. Gibson of the Mayo Clinic, if you are experiencing extreme under-eye bags and puffiness and have also noticed swelling in other parts of your body, this could be an indication of thyroid or kidney problems or the side effect of medicine you are taking.

Genetics

Genetics play a role in whether you will develop under-eye bags and to what extreme, according to Dr. Ellen Marmur, chief of dermatologic and cosmetic surgery at Mt. Sinai Medical Center in New York. You may have an anatomic, structural, genetic issue that results in eye bags. Look at your parents. Do they have under-eye bags? As we age, the skin in the eye area becomes less elastic and thinner. The fat that lies underneath the skin starts to bulge, which creates the bags, according to Dr. Paul Lazar, professor of clinical dermatology at Northwestern University in Chicago.

Allergies, Lifestyle, Hormones

According to Dr. Mary Stefanyszyn, associate surgeon in ophthalmology at Wills Eye Hospital in Philadelphia, under-eye swelling can be caused by something that you've eaten, such as strawberries, or from sleeping on feather pillows (see mothernature.com). If you've eaten a lot of salty foods the night before or didn't get enough sleep or had your head bent over for a long period of time, this can cause swelling and puffiness. Hormones, right before and during your menstrual period, can make your under-eyes puffy.

Graves' Disorder

Graves' disease is a thyroid condition. If you are suffering from it, you may have bags or roundish pouches under your eyes. Under-eye bags can also be a sign of a kidney problem.