I was just looking up foods to eat for healthy hair, and came across something that says hair extensions can cause hair loss- PERMANENT bald patches that wont regrow no matter what. Not just hair extensions but also tight ponytails and buns. I live in my tight ponytails! Apparently this kind of pulling, tugging, and tightness on the hair ruins it- either thins out, falls out, and damages the follicle enough that it never re grows. I never knew that!