Dodgy maths a problem (6)
I believe the answer is:
asthma
'problem' is the definition.
(I have seen 'Respiratory problem ' mean 'asthma' so perhaps 'problem' could also mean 'asthma')
'dodgy maths a' is the wordplay.
'dodgy' indicates anagramming the letters (a dodgy or wrong order of the letters).
'maths' with letters rearranged gives 'asthm'.
'asthm'+'a'='ASTHMA'
(Other definitions for asthma that I've seen before include "Physical disorder" , "Respiratory problem" , "Respiratory disease" , "inspiring trouble" , "Breathing complaint" .)