Doctor wrong to get involved in lip disorder (8)
I believe the answer is:
ringworm
'disorder' is the definition.
(ringworm is a kind of health problem)
'doctor wrong to get involved in lip' is the wordplay.
'doctor' is an anagram indicator.
'to get involved in' means one lot of letters goes inside another.
'lip' becomes 'rim' (synonyms).
'wrong' is an anagram of 'ngwor'.
'ngwor' going within 'rim' is 'RINGWORM'.
(Other definitions for ringworm that I've seen before include "Problem with skin" , "Fungal infection of the skin characterised by round patches" , "Tinea" , "Skin disease" , "ailment" .)