A system for improving a hair condition, comprising: a sensor device having at least one sensor for detecting a hair condition parameter; and a treatment device comprising: a lighting device for illuminating a scalp of a user with light; and an electronic circuit device coupled to the sensor device for receiving the detected hair condition parameter and/or a treatment parameter determined from the hair condition parameter by means of the sensor device, wherein the electronic circuit device is designed to control the illumination of the scalp of the user with light by means of the lighting device on the basis of the received detected hair condition parameter and/or the treatment parameter, wherein the treatment device comprises at least one further treatment element, wherein the treatment element comprises an application device for a cosmetic treatment agent, a massage device, a heating device and/or a cooling device, and wherein the electronic circuit device is also designed to apply the cosmetic treatment agent, to perform a massage, to heat the scalp and/or the hair and/or to cool the scalp and/or the hair on the basis of the received detected hair condition parameter and/or the treatment parameter. a sensor device having at least one sensor for detecting a hair condition parameter; and a treatment device comprising: a lighting device for illuminating a scalp of a user with light; and an electronic circuit device coupled to the sensor device for receiving the detected hair condition parameter and/or a treatment parameter determined from the hair condition parameter by means of the sensor device, wherein the electronic circuit device is designed to control the illumination of the scalp of the user with light by means of the lighting device on the basis of the received detected hair condition parameter and/or the treatment parameter, wherein the treatment device comprises at least one further treatment element, wherein the treatment element comprises an application device for a cosmetic treatment agent, a massage device, a heating device and/or a cooling device, and wherein the electronic circuit device is also designed to apply the cosmetic treatment agent, to perform a massage, to heat the scalp and/or the hair and/or to cool the scalp and/or the hair on the basis of the received detected hair condition parameter and/or the treatment parameter. a lighting device for illuminating a scalp of a user with light; and an electronic circuit device coupled to the sensor device for receiving the detected hair condition parameter and/or a treatment parameter determined from the hair condition parameter by means of the sensor device, wherein the electronic circuit device is designed to control the illumination of the scalp of the user with light by means of the lighting device on the basis of the received detected hair condition parameter and/or the treatment parameter, wherein the treatment device comprises at least one further treatment element, wherein the treatment element comprises an application device for a cosmetic treatment agent, a massage device, a heating device and/or a cooling device, and wherein the electronic circuit device is also designed to apply the cosmetic treatment agent, to perform a massage, to heat the scalp and/or the hair and/or to cool the scalp and/or the hair on the basis of the received detected hair condition parameter and/or the treatment parameter.