What Causes Hairs On The Chin And Nipples?

I have a problem with singular hairs on my body such as on my chin, left shoulder, nipples and pubic area. Theyre unique to the others and stand out.They are darker, much thicker, and can sometimes be inflammed. I have tried plucking them out from under the skin. Once they are tweezer out, the full length of the hair is much longer than what was previously on the surface. What is it?