IME it depends on the cause. For me that was three main things.
My self centred way of thinking and acting seemed to put me in conflict with those around me. Not always directly, often I was disappointed in they way they acted as opoosed to how I thought they should be acting.
I had some secrets, events that happened whuile I was drunk that completely destroyed my personal values. I didn't know who had observed me, or if I had been seen at all, and I was contantly worried about being found out. Some of the memories really were a nightmare.
Then there were the people I had hurt. Looking over my shoulder, expecting a tap, crossing the street to avoid certain people, and worrying about what they were saying to others that might let my secrets out. There was allso some guilt from ripping people of, damaging their property, and lying and blaming others.
Carrying all that around, the least I could expect was a bit of anxiety. In reality, I could not stay sober until I had addressed all those issues.