Hair Care and Treatments
Domain 2, Hair Care and Treatments, tests hair structure, growth, scalp conditions, and the professional selection of shampoos, conditioners, and treatments. The exam expects you to match product chemistry and service technique to the client’s hair properties rather than recommend products by habit.
Core rules
- The hair shaft has three layers: cuticle (protective outer scales), cortex (bulk, strength, pigment), and medulla (central core, not always present).
- Porosity governs how quickly hair absorbs and loses moisture; high-porosity hair accepts treatments quickly but loses moisture easily.
- Elasticity is the ability to stretch and return; low elasticity signals weak, over-processed hair.
- The growth cycle has anagen (active growth), catagen (transition), and telogen (resting/shedding) phases.
- Shampoos rely on surfactants; conditioners lower pH, smooth the cuticle, and reduce friction.
Worked example
A client with color-treated, high-porosity hair reports roughness and quick moisture loss. Recommend a low-pH moisturizing conditioner, reduce heat styling, and schedule a light protein treatment only if the hair is also weak. Reasoning: high porosity means the cuticle is raised, so moisture escapes and rough feel is likely. A low-pH conditioner helps close the cuticle; heavy protein is not automatically right because excess protein can make hair brittle.
Traps that cost marks
- Saying conditioner permanently repairs hair; it improves manageability and temporarily smooths the cuticle.
- Confusing density (number of hairs per square inch) with texture (diameter of each hair).
- Assuming a medulla is always present; fine hair may lack one.
- Recommending aggressive scalp massage or treatment on inflamed scalp conditions instead of referring.