Sleeper's woe (5)
I believe the answer is:
apnea
'sleeper's woe' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for apnea that I've seen before include "that'll make you catch your breath?" , "Cessation of breathing during sleep (US spelling)" , "stopping breathing in US" , "Loss of breath" .)