Most dreams about an ambulance involve feelings of emergency, or panic. Often the dream involves some injury or life threatening situation to someone, so therefore concerns the stress felt by some part of our personality. See: accident.
How to deal with such anxiety is important and it can be done – but not without work.
Useful Questions and Hints:
What has happened, or is happening, to make you need external help or feel in an emergency situation?
Are you feeling anxious about a family member of someone close?
What emergency or injury is shown in the dream, and how might this relate to your daily life?
Is it easy to get help in the dream – if not are you feeling alone and unsupported? It might help to read and use Dealing with Fear.