Back Pain: What is your back trying to tell you?

Source : About.com Health

Have you ever had back pain? Chances are if you are reading this article, this answer is yes. As a matter of fact, chances are even if you are not reading this article, this answer is still yes. Over 90% of people will experience back pain at some point in their life. Many people with arthritis will also have their back effected. The question that many people ask is, where is my back pain coming from? Is it something serious?

That’s a question that is difficult to answer as the differential diagnosis for back pain is one of the most broad in medicine. Back pain can be a sign of a simple muscle strain (“Pulling your back”), herniated disc, a multitude of other back problems, or in rare cases even serious medical conditions.

In order to help distinguish between some of these problems, back pain can be broken up into 3 different types of pain: local pain, referred pain, and radicular pain.

     

Local Pain
Local pain is caused by the muscles, ligaments, bones and joints surrounding the spine. It is also sometimes called “axial” back pain. This type of pain is typically dull, aching, steady, worse with movement of the affected part, and worse with palpation of the pain generator. A key feature of axial back pain is that it occurs in the same general region as the pain generator. Local/axial back pain from pulled muscles/ligaments surrounding the spine is by far the most common type of pain.

Referred Pain
A pain generator that is separate in location from when the pain occurs causes this type of pain.  There are two general types. First is pain referred to a second location that is embryological related to the pain generator. This happens as multiple structures arise from a single group of cells during development. This group of cells is called a somite.

This is explanation can lead to a problem in the lower back causing hip or knee pain. The second type of referred pain comes from internal organs. Problems with structures in the belly such as your pancreas, gall bladder, aorta, and multiple others can actually present as back pain.

Radicular Pain
The third and last type of pain comes from irritation or compression of the nerve roots. This is a sharp, shooting, electric, sometimes burning type pain that radiates from your back down to your arms or legs. The most common type of this pain is sciatica, which happens when the nerve roots of the lower back/sacrum are irritated or compressed. Any motion that puts the effected nerve root on stretch will reproduce this pain.

Many etiologies of back pain result in multiple types of pain being produced. This does however provide a starting point from which to think about what is causing the back pain in the first place. In the great majority of cases back pain is "axial" in nature and is mechanical (meaning from the muscles/ligaments/bones surrounding the spine) in etiology. The good news is that 85% of axial back pain completely resolves if it is not accompanied by radicular pain or more serious symptoms.

I hope this brief review of types of back pain is helpful/informative/interesting. It provides some context to why back pain can be such a difficult symptom to find a specific diagnosis for. Physicians have a difficult job of taking clues that these types of pain provide, incorporating them with the clues in the "patient history" or specifics of how patients present, and synthesize that material with any relevant imaging such as X-rays, CT or MRI.