Complaint the compiler will head (7)
I believe the answer is:
illness
'complaint' is the definition.
(illness is a kind of health problem)
'compiler will head' is the wordplay.
'compiler' becomes 'I' (the person who is writing these clues).
'will' becomes ''ll' (contracted form, as in 'he'll' - 'he will').
'head' becomes 'ness' (ness is a headland).
'i'+'ll'+'ness'='ILLNESS'
'the' is the link.
(Other definitions for illness that I've seen before include "Upset" , "Indisposition, sickness" , "suffering this" , "Period of sickness" , "Ailment, disorder" .)