Hair coloring is the practice of changing the color of hair. It can be done for a variety of reasons, including fashion, to cover gray hair, or to correct a previous coloring mistake. There are two main types of hair coloring: permanent and semi-permanent. Permanent hair coloring uses chemicals to change the hair's natural pigment, while semi-permanent hair coloring coats the hair shaft with a colored dye that gradually fades over time.
There has been some concern that hair coloring may cause cancer. However, the evidence on this issue is inconclusive. Some studies have suggested that hair coloring may be linked to an increased risk of certain types of cancer, such as leukemia and lymphoma. However, other studies have not found this link. Overall, the evidence on the relationship between hair coloring and cancer is mixed.
