How hair can be damaged.
Although scalp hair is hardy, and can withstand a lot of abuse, it can be damaged by too much or inexpertly applied perming, dyeing - Blonde to Brunette, bleaching and massage. The amount of beautying the hair can take varies from person to person. Occasionally the scalp is allergic to the dye and becomes inflamed and swollen. To prevent this occuring, the dye should be tested by applying it to a small area on the arm. If a patch of inflammation has developed, the dye must not be used on the hair. Most people who bleach their hair do so with hydrogen peroxide. If the peroxide is repeatedly applied, it may make the hair brittle. If this happens the hair may turn rough, develop split ends, or become thinned or shortened.