Disease leads to youth suffering with his lip damaged (8)
I believe the answer is:
syphilis
'disease' is the definition.
(syphilis is a kind of health problem)
'leads to youth suffering with his lip damaged' is the wordplay.
'leads to' suggests taking the first letters.
'with' says to put letters next to each other.
'damaged' is an anagram indicator.
The initial letters of 'youth suffering' is 'ys'.
'his'+'lip'='hislip'
'ys' put after 'hislip' is 'hislipys'.
'hislipys' anagrammed gives 'SYPHILIS'.
(Another definition for syphilis that I've seen is " Venereal disease".)