An alcoholic drink leads to a complaint (6)
I believe the answer is:
angina
'complaint' is the definition.
(angina is a kind of disease)
'an alcoholic drink leads to a' is the wordplay.
'alcoholic drink' becomes 'gin' (I've seen this before**).
'leads' says to put letters next to each other.
'an'+'gin'+'a'='ANGINA'
(Other definitions for angina that I've seen before include "Cardiac complaint" , "Sharp chest pain caused by heart disease" , "Painful heart condition" , "Severe pain from heart disease" , "Painful heart complaint." .)