Pain is a pain!  Actually, from one standpoint pain is a good thing - it is our body's way of letting us know that something is not right or that we have been injured.  When we are injured, our nervous system use a complex pathway of nerves to inform our brain that something bad has happened.  Our nervous system interprets the quality of the pain (such as sharp or dull or achy or hot, etc.) and the location of the pain.  An increase in our pain tells us that our current activities are aggravating the injury while a decrease in pain tells us that we are improving. 

In many cases our pain is acute.  Acute pain is of recent onset and is most often related to a recent injury like a car accident, a fall or some other recent injurious event.  More often than not, acute pain is a one time episode - it comes, makes us miserable, it leaves and doesn't come back.

Chronic pain, on the other hand, is pain that can drag on for months, years or a lifetime.  The medical definition of acute pain is pain that has been present for more than three months or 90 days.  There are times that chronic pain is entirely gone but then rears its ugly head in an acute flair-up.  This is commonly referred to as an acute flair-up or exacerbation of a chronic problem.