Very busy hospital, one got upset about it (2,3,2)
I believe the answer is:
on the go
'very busy' is the definition.
(I've seen this before)
'hospital one got upset about it' is the wordplay.
'hospital' becomes 'h'.
'upset' indicates anagramming the letters.
'about it' means one lot of letters goes inside another.
'one'+'got'='onegot'
'onegot' anagrammed gives 'ontego'.
'h' going into 'ontego' is 'ON THE GO'.
(Other definitions for on the go that I've seen before include "Ever busy" , "Active, in constant motion" , "Busy and active" , "ready to start monopoly?" , "Busily active" .)