How concerned do I have to be that my hair is falling out?

I always kind if used to “shed” a lot my hair is all over my clothes and pillows and stuff. But now when I leaf my fingers through my hair a noticeable amount of strands latch on and come out. Im not loosing patches of hair you cant see my scalp but just dozens of hairs are falling out. Should I be worried about this? What could be causing it?