Dry skin (xerosis) develops when the skin produces insufficient natural oils and barrier lipids — particularly ceramides, cholesterol, and fatty acids. This weakens the skin barrier and increases transepidermal water loss (TEWL), leading to tightness, roughness, and flaking.

Dry skin may be influenced by:

• Genetics
  
• Hormonal changes
  
• Ageing
  
• Certain medical conditions
  
• Harsh cleansers or over-exfoliation
  
• Cold weather, low humidity, or UV exposure
  
• Inadequate nutrition or hydration
  

Dehydrated skin, by contrast, lacks water rather than oil. It often occurs when the barrier is compromised and unable to retain moisture, even in skin that produces adequate sebum.

Common triggers for dehydration include:

• Dry climates or air-conditioned environments
  
• Overuse of cleansers
  
• Long-haul travel
  
• Hormonal fluctuations
  
• Skincare routines that lack sufficient humectants or emollients
  

When the barrier is impaired, the skin may appear dull, flaky, or papery and feel tight, itchy, or sensitive. Makeup often sits poorly, and even gentle products may cause stinging.

The priority in both conditions is barrier repair.

Replenishing lipids and restoring hydration allows the skin to retain moisture effectively. Once the barrier is stable, active ingredients such as vitamin C or exfoliants can be introduced safely.