Complaint from boy stuck in tree (6)
I believe the answer is:
malady
'complaint' is the definition.
(malady is a kind of health problem)
'boy stuck in tree' is the wordplay.
'boy' becomes 'lad' (informal term for boy).
'stuck in' is an insertion indicator.
'tree' becomes 'may' (I've seen this in other clues).
'lad' put inside 'may' is 'MALADY'.
'from' is the link.
(Other definitions for malady that I've seen before include "Sickness, ailment" , "Complaint" , "affection" , "Illness or disease" , "hay fever, perhaps" .)