Patient's woe (7)
I believe the answer is:
relapse
'patient's woe' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for relapse that I've seen before include "Fall back (into ill health)" , "New downturn in health" , "falling back" , "Deteriorate in health" , "Downturn in health (after improvement)" .)