Slum area’s hospital within reach (6)
I believe the answer is:
ghetto
'slum area's' is the definition.
(I've seen this before)
'hospital within reach' is the wordplay.
'hospital' becomes 'H' (abbreviation for hospital).
'within' means one lot of letters goes inside another.
'reach' becomes 'getto' (synonyms).
'h' put within 'getto' is 'GHETTO'.
(Other definitions for ghetto that I've seen before include "run-down part of town" , "Segregated area" , "A poor quarter of a city" , "poor part of town" , "Needy part of city" .)