Over-hydration, also known as barrier saturation, does not occur from drinking too much water, but from overwhelming the stratum corneum (the outermost layer of the skin) with too many humectant-heavy products, such as serums, essences and creams. While the intention is good, the result is compromised skin barrier function.
Swelling: Does your skin look visibly puffy, overly smooth and almost 'waterlogged', to the extent that it loses its natural texture? If so, you are probably applying too much product.