Dic: on edge

• My nerves were constantly on edge.
• You're always on edge waiting for an important call, because you don't really know when that phone will ring.
• I have really been on edge lately.
• Why are you so on edge?

1. [PHRASE][usu v-link PHR] If you or your nerves are on edge, you are tense, nervous, and unable to relax.

2. on edge: nervous or worried.

Usage notes: often used in the forms set you on edge or put you on edge: The accident set us on edge for several days.

cf. (live) on the edge

1. to be in an uncertain situation or one that could cause harm:

• I do not believe a person has to live on the edge in order to be a creative artist.
  Related vocabulary: live dangerously

2. to be very poor:

• Too many children live on the edge, without proper food or medical care.

.... Cobuild, http://idioms.thefreedictionary.com/edge