What causes puffy eyes and dark circles under the eyes?
Ordinary swelling around the eyes means you have an excessive accumulation of fluids, called oedema, in surrounding skin tissue.
Because the skin around the eyes is the thinnest skin in the body, swelling and discolouration can be quite prominent.
But why does fluid accumulate to form puffy eyes in the first place?
Edema around the eyes generally results from a variety of factors, including:
• Overconsumption of salt, which causes fluid retention
• Seasonal allergies that can cause inflammation and swelling
• Sinus problems
• Fatigue and lack of sleep
• Inherited facial features
While the last answer isn’t very satisfying, many people indeed have puffy eyes because this trait simply runs in the family.
Eye puffiness can occur when the fatty tissue that ordinarily protects the eye inside the bony eye socket begins to push forward and fill in spaces below the eye.
This happens because ageing processes cause thinning of the membrane or “septum” that ordinarily holds back fat in both the upper and lower eyelids. As the membrane thins, the fat herniates and pushes forward. This is when bags or bulges start forming under the eye.
Why are eyes sometimes puffier in the morning after you wake up?
While we sleep, we don’t blink. And this is part of the reason why eye puffiness develops.
Blinking for eyelids is like walking for legs. When idle, some people develop swelling in their lower extremities. This usually goes away as soon as they start walking and muscles in the legs begin “milking” the trapped fluids (edema), which are released back into circulation.
A similar action takes place in the eyelids. The closed, non-blinking eyelids during sleep potentially can swell in certain people prone to this problem. So in the mornings, you could wake up with unusually puffy, swollen eyelids. As soon as you open your eyes and start blinking, some of the swelling will diminish in an hour or so.
When do puffy eyes mean you have a medical condition?
When puffy eyes occur unexpectedly, this can signal an underlying medical problem. For example, people with thyroid eye disease can develop swelling of tissue and muscles around their eyes. Also, bulging eyes can signal a thyroid disorder known as Graves’ disease.
Eye allergies related to conditions such as hay fever also can cause swollen eyes. Other types of allergies, such as reactions to certain foods or chemicals, can cause swollen eyelids.
During an allergic reaction, certain cells in the body release a chemical called histamine that has many adverse effects on body tissues, including fluid leakage from the blood vessels. These fluids become trapped in surrounding tissues, causing oedema.
Puffy, swollen eyelids and dark circles under the eyes can occur when you have an eye infection such as pink eye. These swollen eyes are caused by inflammation associated with eye infection, which directly affects the neighbouring eyelids. Also, dry eyes can cause general puffiness and swelling.
Systemic diseases, including kidney failure, can also lead to general swelling throughout the body, including around the eyes.