People mistakenly think dehydration and dry skin are the same, and they aren’t.
Dry skin equals insufficient oil in the skin whereas dehydration is inadequate water in side the entire body. Both affect the skin. When either occurs, particularly on a persistent basis, the skin can become sensitized. Sensitized skin is skin that your actions or the environment has made sensitive, not necessarily skin that reacts quickly to products. For example, sunburn, harsh products and windburn can make skin sensitized.
You can almost always control and improve dehydration with increased water intake and reducing alcohol, caffeine, and sodium; however, dryness often requires lifestyle changes and adaptations like identifying quality products, reducing the temperature and length of showers, and possibly seeing your dermatologist for chronic excessive dryness (possible eczema).