In short. Dry skin is water loss, not a lack of oil. What causes xerosis, how moisturisers actually work, and the daily habits that keep skin dry.
Key points
- Short lukewarm showers; a mild non-foaming cleanser used only where it is needed; patting rather than rubbing dry; applying moisturiser within a few minutes while the skin is still damp; humidifying indoor air in winter; and stopping the exfoliants, scrubs and heavily fragranced products that keep stripping the barrier.
Dry skin, or xerosis, is a state in which the skin loses water faster than it can hold it. The surface feels tight and rough, looks dull, and may flake, itch or crack. It is common, it worsens with age and in winter, and it is very often maintained by the things people do to treat it.
What actually causes it
The skin barrier is a layered structure of flattened cells embedded in a matrix of lipids, with natural moisturising factors inside the cells that hold water. Water leaves through it constantly; the barrier keeps that rate low. Anything that removes lipids or damages the cells raises the rate. Soap and foaming cleansers, hot water, long showers, frequent swimming, solvents, harsh exfoliants and over-use of retinoids all do it. Cold dry air, indoor heating and air conditioning do it. Age reduces lipid production. Some medicines, notably oral retinoids and diuretics, contribute. Underlying conditions including eczema, psoriasis, thyroid disease and diabetes also cause dry skin, and these need to be identified rather than moisturised over.
What moisturisers actually do
Moisturisers do not add water to the skin in any lasting way. They work in three ways. Humectants such as glycerin and hyaluronic acid attract and hold water in the outer layer. Emollients fill the gaps between cells and make the surface smooth. Occlusives such as petrolatum and dimethicone slow water loss by forming a film. A product combining all three performs better than one relying on a single mechanism, and the vehicle matters as much as the headline ingredient.
Applied to damp skin immediately after washing, a plain moisturiser works better than an expensive one applied to dry skin. Thicker formulations are not automatically better, but they are usually more effective for very dry skin.
What actually helps xerosis
Short lukewarm showers; a mild non-foaming cleanser used only where it is needed; patting rather than rubbing dry; applying moisturiser within a few minutes while the skin is still damp; humidifying indoor air in winter; and stopping the exfoliants, scrubs and heavily fragranced products that keep stripping the barrier.
Itching, cracking and infection
Dry skin itches, scratching damages the barrier further, and cracked skin can become infected. Redness, weeping, crusting or increasing pain in dry cracked skin suggests infection and needs medical assessment. Dry skin that does not improve with consistent and correct moisturising is a reason to look for an underlying cause rather than a stronger cream.
See a doctor if
- Skin is cracked, weeping, crusted or increasingly painful, which may mean infection.
- Dryness is severe or generalised, or is unresponsive to consistent moisturising and barrier care.
- Dry skin comes with fatigue, weight change, cold intolerance or excessive thirst, which may point to thyroid disease or diabetes.
Frequently asked questions
Do moisturisers add water to the skin?
Not in any lasting way. They work in three ways: humectants attract and hold water in the outer layer, emollients fill the gaps between cells and smooth the surface, and occlusives slow water loss by forming a film. A product combining all three performs better than one relying on a single mechanism.
When is the best time to apply moisturiser?
Within a few minutes of washing, while the skin is still damp. A plain moisturiser applied to damp skin works better than an expensive one applied to dry skin. Thicker formulations are not automatically better, but they are usually more effective for very dry skin.
What if dry skin does not improve with consistent moisturising?
That is a reason to look for an underlying cause rather than a stronger cream. Eczema, psoriasis, thyroid disease and diabetes all cause dry skin, and these need to be identified rather than moisturised over.
Risks & Limitations
- Skin quality changes gradually. Improvement is measured in months, not days, and maintenance is continuous.
- No product, device or procedure reverses ageing; treatments improve particular features, partially and for a limited time.
- Over-treatment — too many active ingredients, peels or energy sessions too close together — damages the barrier and makes skin look worse.
- Energy devices and deeper peels can cause burns, blistering, prolonged redness and post-inflammatory pigmentation, with a higher risk in darker skin tones.
- Skin boosters and other injectables carry risks of bruising, swelling, irregularity and, rarely, vascular complications.
- Results vary with skin type, age, sun exposure, adherence to the routine, and individual healing response, and cannot be predicted with certainty.
- Sun protection is essential to any plan; without it, pigment and texture improvements are lost.
When to Seek Care
- Blistering, broken skin, weeping or crusting after any product or procedure — stop and seek medical review.
- Spreading redness, swelling, pain or pus, or fever with a skin change.
- A new or changing pigmented lesion, or a spot that bleeds, itches, crusts or fails to heal.
- Severe reaction to a topical product, or swelling of the face, lips or throat — seek emergency care.
- Dryness, redness or flushing that persists despite weeks of genuinely gentle care, which may indicate eczema, rosacea or a systemic cause.
References & Further Reading
- American Academy of Dermatology (AAD) — public and clinical guidance on skin care and photoprotection
- American Society for Laser Medicine and Surgery (ASLMS) — guidance on energy-based treatment and safety
- Chinese Medical Association, Dermatology Branch — clinical guidance
- Cochrane Library — systematic reviews in dermatology and skin care
- World Health Organization (WHO) — ultraviolet radiation and skin health resources
This page is patient education, not medical advice, and it does not cite individual studies. Discuss your own case with a qualified clinician. To arrange an assessment at Chongqing West District Hospital, see Contact & Consultation.