QQI Level 5 Beauty Therapy key terms

The outermost, avascular layer of the skin, made of stratified keratinised epithelium. It renews itself continuously and provides the main barrier against water loss, microbes and irritants.

The living layer beneath the epidermis, containing collagen and elastin fibres, blood vessels, nerves, glands and hair follicles. It gives skin strength, elasticity and nourishment, and it is where most skin reactions occur.

The uppermost layer of the epidermis, composed of flattened, dead keratin-filled cells held together by lipids. It controls water loss and is the layer most affected by exfoliation and topical products.

A tough fibrous protein forming the main structural material of skin, hair and nails. Its content and arrangement determine hardness, water resistance and flexibility of these tissues.

A gland in the dermis, usually attached to a hair follicle, that secretes sebum onto the skin surface. Sebum lubricates skin and hair, and overactivity contributes to oily skin and comedones.

The main structural protein of the dermis, forming a supportive network of fibres. It gives skin tensile strength; ageing and ultraviolet exposure reduce and damage it, causing laxity and lines.

A resilient protein fibre in the dermis that allows skin to stretch and recoil. Loss or damage to elastin reduces skin firmness and contributes to sagging and wrinkle formation.

A network of vessels and nodes that drains excess tissue fluid and supports immune defence. In the salon it is relevant to facial and body massage, which is directed to encourage lymphatic drainage.

A classification of skin based on its typical oil and water balance, such as normal, dry, oily or combination. It is generally inherited and changes slowly, unlike a temporary skin condition.

A temporary or treatable state of the skin, such as dehydration, sensitivity, congestion or ageing. It differs from skin type and is identified during consultation so treatment and products can be adapted.

The central facial area covering the forehead, nose and chin, where sebaceous glands are densest. It is commonly oilier than the cheeks, which is why combination skin is so frequent.

A blocked pore formed when sebum and dead skin cells accumulate in a hair follicle. An open comedone is a blackhead; a closed one is a whitehead. Extraction must follow safe, hygienic technique.

A lack of water in the stratum corneum, producing tightness, fine lines and dullness. It can affect any skin type, including oily skin, and is often improved by humectant products and gentle care.

Any condition, medication or circumstance that makes a treatment unsafe or inadvisable, either completely or in a specific area. Identifying contraindications during consultation protects both client and therapist.

A written or electronic form capturing the client's details, medical history, skin analysis, treatment plan, products used and consent. It supports safe practice, continuity of care and professional accountability.

A client's clear agreement to a treatment after being told what it involves, its expected benefits and possible risks. Consent should be obtained before treatment and documented in the client record.

A small controlled application of a product, such as tint or adhesive, to check for an allergic reaction before full treatment. A positive reaction means the treatment must not proceed.

The removal of make-up, sebum, sweat and environmental debris from the skin using a suitable cleanser and gentle technique. It prepares skin for further products and is the first step in most facial treatments.

The removal of dead cells from the stratum corneum by mechanical or chemical means. It improves texture and product absorption, but must be avoided on broken, inflamed or sensitised skin.

The natural shedding of dead cells from the skin surface as part of epidermal renewal. Understanding this process helps the therapist judge how often exfoliation is appropriate.

An ingredient that attracts and holds water in the skin, such as glycerin or hyaluronic acid. Humectants help relieve dehydration and are common in moisturisers and serums.

An ingredient or product that forms a barrier on the skin surface to reduce water loss, such as petrolatum or some oils. Occlusives are useful for dry skin and for protecting compromised skin.

The skin's ability to keep water in and irritants, allergens and microbes out, chiefly through the stratum corneum and its lipids. A damaged barrier leads to dryness, sensitivity and irritation.

The hard, visible part of the nail made of compacted keratin, resting on the nail bed. Its condition reflects health and care, and it must not be over-filed or thinned during manicure.

The thin layer of dead skin at the base of the nail plate that seals the nail against infection. It should be softened and gently pushed back, never cut aggressively, to avoid injury and infection.

The skin beneath the nail plate, rich in blood vessels, which gives the nail its pink colour and supports it. Damage to the nail bed can permanently affect nail growth.

Inflammation or infection of the skin around the nail, often causing redness, swelling and pain. It is a contraindication to nail services on the affected digit and requires referral.

The repeating phases of hair growth, rest and shedding: anagen, catagen and telogen. Waxing is most effective when hair is in the anagen phase, so timing between appointments matters.

The active growth phase of a hair, during which the hair is anchored deepest in the follicle. Hair removed in this phase is less likely to regrow quickly, making it the ideal target for waxing.

A hair removal method using warm or hot wax applied in the direction of hair growth and removed against it. Correct temperature, patch testing and skin support reduce the risk of burns and irritation.

The outline and balance of the brow, planned to suit the client's bone structure and features. It should be agreed before hair removal so the client's expectations and natural shape are respected.

The principles of how colours combine and contrast, used in make-up to correct tones and complement skin. For example, green neutralises redness and peach can soften dark circles.

Selecting a base product whose shade and undertone blend with the client's skin in natural light. Testing on the jawline helps avoid a visible line and ensures a natural finish.

The transfer of microorganisms from one person or object to another, directly or indirectly. Hand hygiene, tool disinfection and single-use items are the main controls in a salon.

A process that reduces the number of harmful microorganisms on tools and surfaces, usually with an approved chemical agent. It is required for reusable implements between clients and does not guarantee spore destruction.

A process that destroys all microorganisms, including spores, on an item. It is used where items contact broken skin or body fluids, and requires suitable equipment and validated procedure.

Routine infection-control measures applied to every client regardless of known health status, including hand hygiene, gloves and safe waste disposal. They assume all blood and body fluids may be infectious.

The limits that keep the therapist-client relationship safe and appropriate, covering personal disclosure, physical contact, gifts and social contact. Clear boundaries protect both parties and support trust.

The legal and ethical duty to keep client records confidential, secure and used only for their intended purpose. Clients have rights over their personal information, and breaches must be handled properly.