The basic facts
One of the skin's main functions is to trap moisture. It does so through the stratum corneum (the outermost part of the skin's top layer, or epidermis), which is in direct contact with the environment. The epidermis produces lipids, oily substances that limit the passage of water into or out of the skin. Skin that's deficient in lipids can't retain moisture. And with the loss of water, cracks and small cuts develop on the stratum corneum—which can trigger itchiness and introduce bacteria (and even infection) into the skin.
Redness or itchiness Discoloration and the urge to scratch may indicate that your skin isn't properly hydrated.
Overexposure Areas that are uncovered (such as the face) bear the brunt of moisture-zapping wind, but arms, legs, and feet are also susceptible to dryness because they have few oil glands to keep them lubricated.
Advanced age As we get older, our oil glands produce less sebum (oil), which further dries out skin.
Clean up quickly It's tempting to take a long, hot bath or shower when it's chilly out, but try keeping tub time down to three minutes and washing with warm, not hot, water to avoid rinsing away skin-protective oils.
Lather less Cleanse with mild, fragrance-free body and face washes (scents can irritate dry spots).
Moisturize often Apply cream with hydrating ingredients like glycerin and urea, which bind moisture to skin, after showering in the morning and again before bed.
EXPERT STRATEGY If you've tried these tips but are still having trouble, check with a dermatologist to make sure you don't have eczema, seborrheic dermatitis, or a more serious condition.