Summer is here and glowing skin is the absolute goal,however, there are a ton of factors that can combine to make your skin look dull.One of the reasons could be dead skin cells.Millions of skins cells shed everyday and the ones that don't fall off natural can leave a grey tint.Stress may also be a factor.Cortisol levels go up when you're stressed and blood goes to your organs, not your face. This can make your skin look sallow.