What are the driving factors for increasing rate of fair falls in early ages?

I don't believe I have ever seen a teenager lose their hair unless they had cancer or some other serious disease.

@jespah , Hi there, here in this post, I am talking about hair loss, literally, hair falls. See, I am 90's kid, I have many friends who had extreme hair fall when they were 18-19 years old and still I know many teenagers who are suffering from hair fall. So, my only concern is what are the driving factors for hair loss/hair fall?

I was actually reminded by a friend - there's genetics.

That's usually the reason you lose your hair at all, including early.