Startle response, inability to concentrate, a couple of our classic PTSD symptoms. Do you have a list of them that you keep handy? It helps me put them in context instead of having them define my day at random. Also, for calming I keep spoken word meditations on my iPod that I stop and play to myself. They're not religious, they're made for us and different situations like you describe. Here's link to one:

https://itunes.apple.com/us/album/quiet-time-guided-spoken-meditation/id392550409

It feels like adrenalin cuz it is. I read that that is a key predisposition to getting PTSD, while some calm down sooner we have an adrenalin metabolism problem.
muji's idea of soothing music works for me too. Though sometimes I need the opposite, sometimes I need to work it out with music like drums. Whether we work it off, or soothe it. oh, there is also bio feedback in which we tell ourselves that we don't need that adrenalin at the moment, and do some centering and relaxation techniques.

One time, I was late for school, and was running for the bus, all adrenalized, and I realized it and told myself,, I don't need this adrenalin cuz I can walk fast without this surge, and I practiced after that the biofeedback and it helped. I guess I'd gotten into a bad habit of anxiety source adrenalin surges, due to past situations.

Thanks for the responses and the link. Oddly enough I just received an iTunes card. Even though I have been diagnosed twice with PTSD I guess I don't always recognize when I am experiencing a symptom. When I read about PTSD the most frequently mentioned symptom is flashbacks. I have never had a flashback. Not one that I can remember anyway, For the past 4 or 5 weeks I have been easily startled, have nightmares, can't concentrate and have a general sense of waiting for something. I have these feelings every day. It is intense for 6 to 10 hours then the worst of it passes but then I just feel exhausted. I will check out the spoken word meditations. I need something to get through the work day. I have a bunch of reports to write and presentations to prepare and I spend half the day blankly staring at the computer screen and wishing I could run away. The work load isn't bigger than usual....I just can't focus.

This would be a major pain in my life. Bipolar is one of my dx'es but I spend far more of my life manic than depressed. Even my depressions have a high energy edge to them. Productive focus is a challenge. Obsessing (unproductive focus) is a different subject. If only I could earn a paycheck from random obsessions...

Frequent exercise breaks are my most consistent solution. When I feel my focus slipping, I stop for some stretches, calisthenics or whatever. I feel like it helps to keep those adrenaline bursts worked off. Sooner is better.

Paying extra attention to my diet seems to help, also. I tend to starve myself, so for me, any attention at all is an improvement.

wishing you could run away - adrenalin again?
I have felt blocked like that sometimes too, and it's a pain when I need to either write something or do some artwork for something. Maybe it would help, like arfie said, when you feel like running away, get up and run around the block, come back and try again.
How to connect with that creative part of yourself when feeling half dissociated.

I have a stand-up work station for this very reason. If I can catch the surges early enough, often I can keep myself on task by getting out of my chair and letting more physical movement into the stream. I often wonder if I am simply hard wired for multi-tasking.

I wish I was. I need to get away from the computer sometimes n sometimes the harder I try the worse it gets, ya know? Can't force my way through writers block, got to just eat, rest, exercise till I can get refreshed so those synapses start clicking.

Is the topic a touchy topic?

Rather than standing, sometimes I lay on my back on the floor. The contact points with my body help me to relax. I just tell myself that I am safe and that nothing's out to get me. Deep, slow breathing works wonders, too. Sometimes, it just takes five of them. I inhale for a count of ten, hold it for two, then exhale for ten. It's amazing what that 30 seconds can do.

i am a jumpy person even a slight touch makes me jumpy! yelling definitely makes me jumpy

Lucky you not to have any flashbacks at all. In my life, if only. But I share the symptom of startle response with you, and that's plenty to have on one's plate, in my experience. Most of the time I can laugh mine off, but sometimes they're just too intense and too serious an adrenaline hit to the heart for humor.