At one time or another, many of us will likely experience lower back pain. It can interfere with work, daily routines and recreational activities. In fact, back pain is the second most common cause of doctor's office visits.

"Acute back pain is really just back pain which only lasts for about 4 to 6 weeks," says Penny Kendall-Reed, co-author of The Complete Doctor's Healthy Back Bible. "Once it starts to go beyond that, we can take a look at categorizing it, either into recurrent pain -- if you're getting more and more episodes of it with intermittent periods of no back pain -- or into chronic back pain which is basically just a back pain which lasts 12 weeks or more on a continual basis."

Most of the time lower back pain can be traced back to an event such as moving boxes, gardening, or performing an activity you're not used to, explains Dr. Stephen Reed, who co-authored The Complete Doctor's Healthy Back Bible with Kendall-Reed. Often, the acute back pain won't manifest itself right away but you'll wake up the next day in terrible pain.

But why do we get that pain? What's happening in our bodies?

"There are a number of causes that are considered. A specific diagnosis or location of damage is often not found," Reed says. "However, what we're assuming is happening is that a small injury to the muscle (such as a small muscle tear that doesn't hurt too much to start with) becomes inflamed over 24 to 48 hours. It's the inflammation that is causing aggravation and sensitization of the local nerves in the back that actually result in a marked increase in pain."

Both Reed and Kendall-Reed stress the importance of being able to describe your pain to your doctor.

"There's a lot of different things we want to look at," Kendall-Reed says. "We want to look at the quality of the pain and the severity of the pain and the type."

"Is your pain radiating down your leg or is it localized around the back? Because that would be indicative of different types of injuries," she says. "Is it more of a lower back pain or is it a disc injury? Or is it actually a leg pain? We also want to look at if it is throbbing, intense, or  stabbing."

Your description of the pain can give your doctor clues to the pain's location and what sort of treatment to pursue. If it's a throbbing pain it's generally muscular and if it's intense it may involve the nerves, Kendall-Reed says.

So who's at risk? According to Reed, everyone, to a certain extent.

If you're relatively unfit and don't stretch or exercise, and you decide to do some heavy lifting or moving, you're taking a big risk.

Most acute back pain will resolve itself in 4 to 6 weeks, but the cauda equine syndrome is one of the rare emergencies in the field of back surgery, Reed explains. It involves an acute and aggressive compression of the nerve roots in the spinal canal. Besides a loss of bladder and bowel control, other symptoms include a progressive weakness and loss of feeling in the legs, particularly in the saddle area between the legs. This needs to be addressed on an emergency basis.