What causes left side back pain?

If you have left side back pain you may have non-specific lower back pain. This is the most common type of back pain.

Without an assessment it is impossible to be sure of the exact cause of anyone’s pain, therefore I recommend that you go along to a doctor or physiotherapist and have an assessment. This will do two things, it will rule out any of the more serious causes of back pain and put your mind at rest, and you will also get specific advice for your problem.

Before I talk any more about left sided back pain you need to know about the three main types of back pain.(1)

Non-specific lower back pain (95% of people with back pain have this type)
Nerve root irritation (less than 5% of people have this type)
Serious back problems – fortunately very few people have this type of problem (less than 1%). Check to see if you have any of the symptoms listed and seek urgent help if you do.

Non-Specific Lower Back Pain

The term non-specific lower back pain is a term used to describe all of the non serious causes of back pain and can include all sorts of problems – several of them can cause left side back pain.

The problem with non-specific lower back pain is that it is exactly that – non-specific. This means that very often there is no obvious cause for the problem. If you are interested I have written more about the different causes of lower back pain.

These are some possible culprits for acute left side back pain which may or may not apply to you:

Facet Joint Strain and Muscle Spasm

A common cause of acute lower left back pain is a facet joint strain and/or back muscle strain. Your spine is made up of large bones called

vertebrae that are separated from one another by spinal discs. However, many people don’t realise that each vertebra overlaps the next and forms a pair of joints called facet joints. These joints enable movement in the spine, they are a bit like little finger joints. If they become a bit sore you may get protective muscle spasm which is where your muscles tighten up to try and protect the painful area, this can really hurt!

Fortunately this problem is not serious and managing it with pain relief and keeping active is usually enough to get the symptoms back under control.

A recent research trial (2) caused a bit of a stir by comparing anti-inflammatory tablets and/or spinal manipulation with simple advice to keep active in non specific acute back pain. The results showed no additional benefit from anything on top of keeping active.

Sacroiliac Joint Pain

The sacroiliac joint is described in more detail in this section. It is a very stable joint with very little movement but problems with the joint can occur if this movement becomes restricted or if there is too much movement in the joint. Too much movement sometimes happens after a fall or injury but most commonly after pregnancy. This is the main cause of pregnancy back pain. This can cause right or left side back pain.

Occasionally the joint becomes inflamed and this may be a sign of ankylosing spondylitis.

Aging Changes

Changes occur in the joints as we age and can cause stiffness and pain in the facet joints of the lower back. This can cause right of left side back pain. Degenerative disc disease tends to cause central pain although pain can be referred outward to a site that is some distance away from the actual sore tissue and changes in the discs can cause strain in the facet joints.

Referred Pain

Referred pain is pain that is felt away from the actual site of the problem. An example is a gall bladder problem that can give you pain in your shoulder blade. The most well known example is a heart attack which may be felt as pain in the left arm.

Muscles and joints can refer pain in a similar way for example a facet joint strain can give you pain in the buttock. This can be very confusing but an experienced clinician can usually spot it.

Chronic versus Acute Pain

This whole thing is further complicated if you have chronic lower back pain, as the way your body responds to pain changes if you have had it for a while. If you have chronic pain bear in mind that it is very difficult indeed to pin point the exact cause of the problem.

My advice is go along and see someone you trust to get a diagnosis. It is highly likely that you will have a very manageable non specific lower back pain problem that you can treat with success.

References

1. Back pain - lower: Simple low back pain - follow-up and reassessment. (2005).at <http://www.cks.library.nhs.uk/back_pain_lower/in_summary/
scenario_simple_low_back_pain_review>
2. Hancock, M. et al. Assessment of diclofenac or spinal manipulative therapy, or both, in addition to recommended first-line treatment for acute low back pain: a randomised controlled trial. The Lancet 370, 1638

11-Jan-2010

Lower Back Pain Toolkit Home Page

Back Pain Symptoms other than left side back pain