What Skin Dryness Really Is
Dry skin - medically called xerosis or xeroderma happens when the outermost layer of your skin loses more moisture than it can retain. It’s one of the most common skin complaints worldwide and spans from a mild seasonal annoyance to a chronic, uncomfortable condition. In clinical terms, dry skin reflects a dysfunction of the skin’s barrier that normally holds water and protects against environmental stressors.
Sources: Mayo Clinic - Dry Skin Symptoms & Causes, MedlinePlus - Dry Skin
Skin Structure and Hydration: How a Healthy Barrier Works
The outermost layer of skin, called the stratum corneum, functions like a brick wall. Corneocytes are the “bricks” flattened, dead cells that contain water. Lipids (fats) form the “mortar” between these cells, sealing in moisture and keeping the barrier intact. A healthy skin barrier limits water loss and prevents external irritants and microbes from entering.
In normal skin, hygroscopic molecules (like urea, lactate, and amino acids) hold water within this layer, while lipids such as ceramides prevent evaporation. When this system is disrupted, water escapes and the skin becomes rough, flaky, and tight. Factors that disrupt this balance both outside the body (external) and inside (internal) can lead to dryness.
Sources: Eucerin - Xerosis Overview, PubMed - Skin Hydration and Barrier Function
External Causes of Dry Skin
1. Climate and Low Humidity
Cold air in winter or hot dry climates lack moisture. Without adequate humidity, water evaporates rapidly from the skin’s surface. Indoor heating and air conditioning further strip humidity from the air, worsening dry skin during winter and in arid regions.
2. Hot Water Exposure and Bathing Habits
Long showers or baths with hot water remove natural oils from the skin’s surface. These oils are essential for moisture retention. Frequent handwashing or excessive bathing strips the barrier faster than the skin can restore it, leading to dryness.
3. Harsh Soaps and Cleansers
Soaps with high pH, sulfates, fragrances, and alcohols disrupt the skin’s mild acidity and lipid layer. These products strip away oils that form a protective barrier, accelerating moisture loss.
4. UV Rays and Sun Exposure
Ultraviolet radiation damages skin proteins and its ability to retain water. Over time, chronic sun exposure impairs skin structure and accelerates aging, making dryness more severe and persistent.
See: Eucerin - Xerosis Overview
5. Occupational Exposure
Certain professions involve repeated water contact, chemicals, or frequent washing. Healthcare workers, hairdressers, cleaning staff, and food service workers often report dry, irritated skin due to these exposures.
See: Occupational Dry Skin - Springer
Internal and Physiological Causes
1. Aging
With age, oil glands produce fewer lipids and sweat glands become less active. This reduces moisture delivery to the skin’s surface and weakens the barrier. Collagen and elastin decline as well, thinning the skin and compromising its integrity.
See: USPharmacist - Dry Skin Causes
2. Hormonal Changes
Hormone fluctuations especially decreases in estrogen during menopause reduce sebum (oil) production. Thyroid imbalances (like hypothyroidism) affect metabolism and oil production, contributing to dryness.
See: American Skin Association - Dry Skin
3. Dehydration and Nutritional Deficiencies
Systemic dehydration means less water is available for skin tissues. Deficiencies in essential fatty acids, vitamins A, D, and E, and minerals like zinc reduce the skin’s ability to repair and maintain its barrier.
4. Genetic Predisposition
Some individuals are genetically more prone to dry skin, due to naturally lower oil production or inherited conditions like ichthyosis. These factors make skin more sensitive to environmental stressors.
See: PubMed - Skin Hydration and Barrier Function
Medical Conditions Associated With Dry Skin
Dryness can also be a symptom of underlying medical conditions. In these cases, the skin’s barrier is compromised by systemic or dermatologic disease processes:
- Eczema (Atopic Dermatitis): Chronic inflammation disrupts barrier function.
- Psoriasis: Rapid cell turnover produces dry, itchy scales.
- Diabetes: Poor circulation and high glucose levels reduce skin hydration.
- Sjögren’s Syndrome: Autoimmune attack on moisture-producing glands.
- Hypothyroidism: Reduced thyroid hormones reduce oil production and circulation.
Symptoms of Dry Skin
The range of symptoms can vary from mild to severe. Common signs include:
- Skin feels rough or tight.
- Flaking, scaling, or peeling.
- Fine lines or cracks, sometimes bleeding.
- Itching that may persist or worsen at night.
- Areas of redness or irritation.
- Thickened or leathery skin in chronic cases.
When to Seek Medical Attention
Most dry skin improves with hydration and barrier-supportive care. But it’s important to see a healthcare provider if:
- Symptoms don’t improve with moisturizers and routine care.
- Skin becomes inflamed, painful, or infected.
- Cracks are deep and bleed.
- You develop thickened or abnormal skin lesions.
- You suspect dryness may be linked to an underlying condition.
See: Mayo Clinic - Dry Skin Diagnosis & Treatment
Conclusion
Skin dryness is not a disease in itself but a symptom of barrier dysfunction. Causes range from environmental exposures like cold air and low humidity, to lifestyle habits like frequent hot showers, to internal factors such as aging, hormonal changes, and medical conditions. Recognizing the underlying causes and caring for the skin barrier with appropriate hydration and protection helps restore skin health and prevent recurrence.