Diffuse Thinning

Does diffuse thinning only happen at the crown? Or can it happen all over the head (sides and back)? Also, if you are diffuse thinning or balding in general, can the sides and back become softer (individual hair becoming weaker and not as thick)? Or should the back and sides not be affected at all (at all as in should be as thick as when you were a kid/ teen)?

For men, thinning and balding occurs in patterns. For some men, crown thinning and balding is a pattern of hair loss, one that I personally had and transplanted it.  If it is diffuse (all over the scalp) then there is a condition called Diffuse Unpatterned Alopecia (DUPA) something we originally defined in the medical literature in the 1990s which is a real problem for those who have it and these men are never candidates for hair transplantation. Diffuse hair thinning occurs in women but it does not occur in pattern and the causes for this are too many to list here.