Hair extensions should not damage your hair if properly installed, cared for and maintained. Some damage can come from going too long in between maintenance visits. It is good to know anytime the extensions are removed there will be a build up of hair, as hair strands shed naturally. When you have hair extensions, your shed hair is trapped in the attachment until you get them tightened and touched up. If there is too much growth in between the scalp and extension the shed hair can get trapped and natural hair can matt.