Disturbs hospital signs (7)

'disturbs' is the definition.
Although both the answer and definition are verbs in their -s form, I don't see how they can define each other.

'hospital signs' is the wordplay.
I cannot really see how this works, but
'hospital' could be 'h' (abbreviation for hospital on maps) and 'h' is found in the answer.
'signs' could be 'arrows' (arrow is a kind of sign) and 'arrows' is found within the answer.
This accounts for all the letters.
This explanation may well be incorrect...

Can you help me to learn more?