Eyes are usually the first thing another person notices about you, or what you may notice about them. Your eyes can say a lot about you in terms of age and health. A number of conditions may be the cause of sunken eyes with dark circles around them, including something as uncontrollable as genetics. For those who do not possess this genetic trait, however, those sunken eyes with dark circles may be caused by something entirely different.
Allergic rhinitis, or allergies, can cause your eyes to sink in and dark under-eye circles to form, according to the University of Maryland Medical Center. There are two types of allergies: seasonal and perennial. Seasonal allergies typically occur during spring and fall when pollen, ragweed and fungus counts change drastically. Perennial allergies last year-round, and are caused by indoor allergies such as dust, dust mites, mold and pet dander. Other symptoms of allergic rhinitis include sneezing, coughing, runny nose, itchy and watery eyes, sore throat and headache. To minimize the effects of allergies, stay indoors when possible, bathe after being outdoors and avoid using fans that draw air into your house from outside. If you suffer from indoor allergies, make sure you dust and vacuum frequently; using HEPA filters can also reduce allergies, according to the University of Maryland Medical Center.
Losing an abundant amount of weight can cause your eyes to sink in and have dark circles around them, according to the Mayo Clinic. As you lose weight, your face will begin to thin. Losing a lot of fat, especially surrounding your face, can make the reddish-blue blood vessels surrounding your eyes more noticeable as they become more transparent. This can also happen as you age and your skin becomes thinner and loses collagen. Unfortunately, you cannot prevent aging but you can take precautions, such as wearing sunscreen on a regular basis and moisturizing your skin regularly, to slow the aging process.
Dehydration can happen to even the healthiest individuals. You can become dehydrated from being outdoors for an extended period of time when it's very hot or humid, or you can perspire so much that you lose a sufficient amount of your body's water content. Dehydration is especially common in the elderly (especially during summer months), children and athletes. Symptoms of dehydration include sunken eyes, low urine output, excessive thirst and dry mouth, according to MedlinePlus.