What is the study of hair called?

The study of hair is known as trichology. This field focuses specifically on the structure, function, and disorders of hair and the scalp. Trichologists explore a variety of topics including hair growth, hair loss, and scalp conditions, providing specialized knowledge that can be crucial for addressing issues related to hair health.

While cosmetology encompasses a broad range of beauty treatments, including hair, skin, and nails, it does not specifically focus solely on hair itself. Dermatology relates to skin health and diseases rather than hair. Hygiene involves practices that ensure cleanliness and health but does not focus on the study of hair. Thus, trichology is the precise field that addresses hair in a detailed and scientific manner, making it the correct answer.