Bags under eyes are sometimes caused by acute inflammation — such as an insect bite or infection of the soft tissue — though these tend to happen on just one side. These cases usually resolve on their own, but more severe cases may require a doctor to prescribe medication. The more common under-eye bags result from a loss of firmness of the skin, a natural part of the aging process.
Several non-invasive techniques can help reduce the appearance of under-eye bags, ranging from cool compresses to topical creams (though results can vary). If you want to remove eye bags more permanently, a cosmetic procedure called blepharoplasty can tighten and smooth out the skin under your eyes.