Bags under the eyes are caused primarily by weakening of the tissue structures and muscles supporting the eyelids, leading to sagging skin and fat displacement. Fluid retention in the area below the eyes can also cause puffiness. Common causes include aging, lack of sleep, fluid retention (often from salty meals), allergies, smoking, genetics, and sometimes medical conditions such as thyroid problems or dermatitis. Lifestyle factors like stress, dehydration, and excessive salt or alcohol intake can also contribute to the appearance of under-eye bags. These factors cause swelling, puffiness, and sometimes dark circles under the eyes.
