Estheticians are licensed professionals who are experts in maintaining and improving healthy skin. An esthetician's general scope of practice is limited to the epidermis (the outer layer of skin) and work in many different environments such as salons, med spas, day spas, skin care clinics, and private practice. Estheticians perform skin treatments that include hair removal (waxing, threading, tweezing, sugaring), facial massage, body treatments (wraps, exfoliation, hydrotherapy), skin care consultations, chemical exfoliation, eyelash and eyebrow tinting, eyelash extensions, aromatherapy, and makeup application. Estheticians may also specialize in machine treatments such as microdermabrasion, microcurrent (also called non-surgical "face lifts"), cosmetic electrotherapy treatments (galvanic current, high frequency), LED (light emitting diode), ultrasound/ultrasonic (low level), and mechanical massage (vacuum and g8 vibratory). The esthetician may undergo special training for treatments such as laser hair removal, permanent makeup, and electrology. Estheticians treat a wide variety of skin issues as long as cosmetic in nature, such as mild acne, hyperpigmentation, and aging skin. Skin disease and disorders are referred to a dermatologist or other medical professional.