Why laser treatment should not be done, these can be side effects.

Redness and irritation. Exposing hair to laser radiation causes the follicles in targeted hairs to be damaged.   

Changes in skin color. Minor color changes in the treated skin are possible.

Skin Infections. Since the hair follicles and its surrounding cells may be damaged during the laser treatment    

Eye injuries      The laser hair removal procedure makes use of powerful lasers. When the area being treated is on the face, there are higher chances that it will pose serious eye injury

A scar is an area of fibrous tissue that replaces normal skin after an injury.