The skin is the body's largest organ, covering an average of 1.8 square metres and performing critical functions including temperature regulation, immune defence, sensory perception, and barrier protection against the environment. Yet skin health is often approached primarily as a cosmetic concern rather than a medical one.
This guide covers the evidence behind good skin health, from everyday care to recognising conditions that need medical attention.
Understanding your skin type
Skin is commonly classified into five types: normal, oily, dry, combination, and sensitive. Knowing your skin type guides appropriate product selection and care routines. However, skin type can change with age, hormones, climate, and health conditions — what worked in your twenties may not suit your forties.
A simple test: wash your face gently and wait an hour without applying anything. If it feels tight and flaky, you have dry skin. If it looks shiny all over, oily. If it shines only in the T-zone (forehead, nose, chin) but feels comfortable elsewhere, combination. If it feels comfortable and looks neither oily nor dry, normal. If it frequently reacts to products with redness, burning, or stinging, sensitive.
Sun protection: the most important skin health intervention
If you do only one thing for your skin health, use daily sun protection factor (SPF) — even on cloudy days. UV radiation from the sun is responsible for:
- 90% of visible skin ageing (wrinkles, pigmentation, loss of elasticity)
- Basal cell carcinoma — the most common cancer in the world
- Squamous cell carcinoma
- Melanoma — the most dangerous form of skin cancer
- Cataracts and eye damage
Current guidelines recommend SPF 30 or above for daily use, with broad-spectrum protection against both UVA and UVB radiation. Apply generously (most people use too little — dermatologists recommend about half a teaspoon for the face alone) and reapply every two hours in direct sun or after swimming.
There are no "safe" tanning methods. Solariums and UV tanning beds increase melanoma risk by 59% when used before age 35 and are banned in many countries.
Common skin conditions and what to do
Acne
The most common skin condition, affecting up to 85% of adolescents and many adults. First-line management includes topical benzoyl peroxide (available without prescription), gentle cleansing, and non-comedogenic (won't block pores) products. Persistent or severe acne warrants GP assessment for topical retinoids, antibiotics, or hormonal treatment.
Eczema (atopic dermatitis)
Characterised by dry, itchy, inflamed skin. The cornerstone of management is consistent moisturising — applying emollients immediately after bathing while skin is still slightly damp. Topical corticosteroids treat flares. Identifying and avoiding triggers (certain soaps, fabrics, allergens) reduces frequency of flares.
Psoriasis
An autoimmune condition causing rapid skin cell turnover producing silvery plaques. Ranges from mild patches on elbows and knees to extensive body coverage. Numerous effective treatments exist from topical preparations to advanced biologics — treatment is highly individual and benefits from specialist input.
Rosacea
A chronic condition causing redness, visible blood vessels, and sometimes acne-like bumps, primarily on the face. Often triggered by sun, heat, alcohol, spicy food, and stress. Topical treatments (metronidazole, azelaic acid), oral antibiotics, and laser therapy are effective. Sun protection is essential.
Tinea (fungal infections)
Athlete's foot (tinea pedis), ringworm, and jock itch are fungal infections treated with topical antifungal creams. Keep affected areas dry; change socks and underwear daily. Persistent or extensive infections may require oral antifungal medication.
Skin cancer: what to look for
Skin cancer is the most common cancer worldwide. The ABCDEs of melanoma are an important self-check tool:
- A — Asymmetry: one half does not match the other
- B — Border: irregular, ragged, or blurred edges
- C — Colour: variation in colour — shades of brown, black, red, white, or blue
- D — Diameter: larger than 6mm (pencil eraser), though melanomas can be smaller
- E — Evolution: any change in size, shape, colour, or a new symptom
Check your skin monthly in a well-lit mirror, including your back and scalp. See your GP promptly for any mole or lesion that changes, bleeds, itches, or concerns you. Do not wait.
Evidence-based skincare basics
Cleansing: Gentle, pH-balanced cleansers once or twice daily. Avoid harsh soaps, scrubs, and hot water, which disrupt the skin barrier. Micellar water or cream cleansers work well for sensitive or dry skin.
Moisturising: Apply moisturiser to slightly damp skin immediately after cleansing. Humectants (hyaluronic acid, glycerin) draw water to the skin; emollients (ceramides, fatty acids) smooth and soften; occlusives (petrolatum, shea butter) seal moisture in. Most moisturisers combine these.
Retinoids: Vitamin A derivatives are among the most evidence-based skincare ingredients for reducing fine lines, uneven pigmentation, and acne. Start with low-concentration retinol available over the counter; build up slowly. Prescription tretinoin is more potent. Always use with SPF as retinoids increase sun sensitivity.
Vitamin C: Topical vitamin C (L-ascorbic acid) has good evidence for brightening, reducing pigmentation, and providing antioxidant protection when combined with SPF. Must be in a stable, opaque formulation.
Diet and skin: High-glycaemic diets worsen acne in susceptible people. Omega-3 fatty acids (oily fish, walnuts, flaxseed) reduce inflammation and improve skin barrier function. Adequate hydration supports skin appearance though it does not directly "hydrate" skin cells.
When to see a dermatologist
See your GP or request a dermatology referral for: suspicious moles or skin lesions, skin conditions not responding to over-the-counter treatment after six weeks, extensive or severe psoriasis, inflammatory conditions requiring systemic treatment, or any skin symptom causing significant concern or distress.
Editorial note: This article was written by the SymptomSense editorial team in accordance with our editorial policy. It is reviewed against NHS, WHO, and Mayo Clinic guidelines and updated regularly. Last reviewed June 2026. This article is for informational purposes only and does not constitute medical advice.