Here's one webpage which explains the symptoms of anxiety attacks and anxiety disorder:
http://www.helpguide.org/mental/anxiety_types_symptoms_tr...
There is, of course, a difference in the occasional anxious moments most of us have, like when we have to speak in front of a group, go in for a review/interview with an employer, or taking a test. Those less-common moments in life--that sort of anxiety is considered pretty typical.
And then, of course, there are those of us who stay awake worrying about things that are unlikely to happen, upset about things we can't change, worried that the sky is going to fall in on our heads. I don't know anyone who hasn't had some of those moments at one time or another.
I have found that having a therapist or counselor to talk to can help. (Sometimes, it really helps to say out loud "I am afraid when the babysitter takes my kid on the train that they're going to get separated." It actually gives our anxiety less power.) If you believe you have some anxiety that could be related to postpartum issues, or if it's causing you trouble in functioning and being present, please see your doctor. They will be able to help refer you to the right person, and talking with that person, you might find out if medication is helpful.
Some prefer to take a more natural approach (I do) and talk to a naturopath. I have had very good results with herbal supplements and tinctures. I can't recommend the supplements to anyone due to body chemistry, however, a tincture of valerian or valerian and hops, taken as directed, can help. If you do try this, start with a lowest dose first. Valerian is the herb that valium is based on; bear in mind, however, that taking too much can have the reverse effect and make a person more wired and anxious, so use thoughtfully. Skullcap can also help with sleep, if this is being affected as well, and again, use strictly according to directions. Herbs are not something to mess with. And like Page suggested, getting out of the house for walks and exercise and a change of scene can help-- avoid the mall, if you can, and try for parks and more serene walking paths.
This can be a trying time of year. Best wishes!