It describes a method for assessing hair conditions, conceived to prescribe a customized cosmetic treatment and/or product, comprising the following steps: A) obtaining information about the hair of at least one user by means of at least one questionnaire with at least one question that combines parameters of tactile perception of hair with at least three attributes, defined by softness, combing and coarseness B) inserting the information obtained in step A in a matrix for classification of hair damages, in order to obtain at least one classification about the hair conditions of the user C) associating the classification about the hair condition of the user obtained in step B with the characteristics of at least one cosmetic product stored in a database that stores registrations of at least one cosmetic product, in order to obtain at least one result about the customized cosmetic treatment and/or product and D) prescribing to the user at least one customized cosmetic treatment and/or product according to the result obtained in step C. It is also describes a system for diagnosing the hair conditions by using at least one matrix for classification of hair damages and one database.
