This must be the most frequent question we get asked as stylists offering hair extensions.
The simple answer is, no. If hair extensions are applied correctly by a qualified and experienced professional, and cared for properly as per the aftercare advise you have been given at your appointment, and removed after the recommended time then no, there should be no damage to your natural hair.
However, there will be some types of extensions more suitable for some hair types than others.
Fusion bonding is suitable for all hair types because it is extremely gentle on the hair. The stylist has complete control over bond size and so can ensure that they are applied weight for weight, allowing no excess tension on the natural hair. The bond also stays put. It cannot slide up and down the hair or rub like micro and Nano rings can. Therefore the hair is safe and contained within a small bond until time for removal.
Wefts need to be applied with caution. The hair needs to be strong and able to hold the weight. If you have fine hair then a mesh can help to evenly distribute the weight more, or the stylist can use finer wefts such as 'handtied wefts' to create the same look with a lesser weight than machine wefts. It will also create a more natural result texture wise.
Extensions should be removed no later than 3 months after installation. This ensures that the natural hair shed does not build up excessively, and can easily be combed out. If your hair grows very fast, you may need to remove them earlier.