What exactly is dehydration...

So many things that can cause dehydrated skin. Our skin gets stripped of moisture by air conditioning, the weather, lack of sleep, not drinking enough water, too-hot showers, using stripping skin care products and not following a good skin care routine.⁠

All skin types can become dehydrated - yes, even oily skin - because it's caused by a lack of water within the skin. Remember that this is a skin condition and not a skin type. So, if the air around is dry or windy, moisture evaporates from your skin.⁠

According to the Simple Skincare website;⁠