Puffy eyes may not always signal lack of sleep. NIH research suggests periorbital edema or puffy eyes can result from fluid retention. In this condition excess water accumulates in the delicate tissues around the eyes. In mild cases, fluid retention can be harmless, but persistent or severe fluid retention can be harmful, depending on the underlying cause. Untreated fluid retention may spread in legs, lungs or around organs, and in severe cases may even lead to kidney or heart issues.
