Trichoscopy of hair and scalp allows viewing of the hair and scalp at X20 to X160 magnifications. The number of hairs in one pilosebaceous unit may be assessed. It may be distinguished whether hair follicles are normal, empty, fibrotic, filled with hyperkeratotic plugs or containing cadaverized hair. Abnormalities of scalp skin color or structure which may be visualized by trichoscopy include honeycomb-type hyperpigmentation, perifollicular discoloration (hyperpigmentation), and scaling. Trichoscopy is an essential tool in the dermatologist armamentarium for diagnosis of causes of hair loss, rare genetic hair shaft abnormalities, and inflammatory scalp diseases.