Dry, itchy skin can lead to more than minor discomfort; low levels of ceramides—lipids that keep water locked in your skin—can cause inflammation that triggers psoriasis, eczema, even acne. Over the long haul, severe dryness can deplete skin's outer barrier, making it vulnerable to environmental damage and upping the risk for visible signs of aging, says Logan.

Beauty fix: Use an antioxidant-rich, plant-based moisturizer with nourishing shea butter, cocoa butter, or natural oils once daily, and twice daily during winter when ceramides need an extra boost. Take fish-oil supplements and eat fatty-acid-rich foods like salmon, shown to help relieve dryness and dermatitis. You can now find natural ceramides in skin-supporting supplements, too, which hydrate skin and reduce inflammation.

Try: Genuine Health Dermalipid; MyChelle Deep Repair Cream