The term is used to describe pain across the lower back. It is not a specific disease but a symptom, which can have different underlying causes. It is very important to distinguish between different forms of low back pain (LBP) and the underlying cause. Almost every person will experience LBP at some point in life. The vast majority is ‘mechanical’ or ‘musculoskeletal’ in nature and no specific diagnosis is made. There are different structures in the spine, which usually play a part: muscles, tendons, discs, small joints (facet joints) and bones. It is often very difficult to pinpoint exactly which part is responsible and in almost all cases it is a combination. However, a good examination and careful analysis of the development of the symptoms by an expert can narrow it down. The pain can be either acute or chronic (longer than 3 months). In cases of acute pain patients can sometimes identify an incident which started it but commonly there is no specific event. Fortunately, the pain settles in the vast majority of cases within a few weeks or months.
In chronic LBP patients often experience intermittent symptoms. At times the patient can be almost symptom free for several weeks or months just to wake up the next morning again with severe pain. This may then take days or weeks to settle.
The influence of so called ‘psycho-social factor’ has been well established. Depression, anxiety, low mood, difficulties at work or in the family can all play a part. This is not to say that these factors cause the pain but they play an important role in the perception and management of the pain. It is an experience of everyone that pain on a good day feels different than on a bad one. It is important that these factors are taken into account and openly talked about during a consultation. It does not mean that the pain ‘is just in the head’ and therefore is not taken seriously. It is the exact opposite!
Low back pain can be a co-existing symptom together with leg pain, which can arise from the facet joints (referred pain) or pressure on a nerve (sciatica /radiculopathy).
Most patients experience pain across the lower back, which feels like a dull ache or spasm. It is often worst in the morning when the back feels very stiff and might take an hour or two to loosen up. It also gets worse when being stuck in the same position (sitting in the car or behind a desk). This is usually due to the back muscled going into spasm. As the muscles get tired in the evening, the back pain may also worsen.
The pain might go up the spine between the shoulder blades and top the neck and often patients feel that it is moving around rather being in the same place all the time. Many patients find it difficult to find a comfortable sleeping position or may wake up when turning in bed.
There can be more sinister causes behind LBP, in which case it is important to make a quick diagnosis. For this purpose, so called red-flag symptoms have been described. The possible causes include tumours, infection, fractures, spondylolisthesis, rheumatism and other rare diseases. The symptoms are not specific for a certain disease and do not mean that there is necessarily a serious cause for the LBP. It is the history and often combination of the symptoms which may give a clue. However, they act as a warning system and patients displaying these should be seen by a specialist and if necessary be investigated quickly.
The following list is not exclusive but covers most of the symptoms:
First presentation age less than 20 or over age 55
Violent Trauma: e.g. fall from a height or accidents
Constant, progressive, non-mechanical pain
Pain in the middle part of the spine (Thoracic pain)
History of cancer
Long term use of steroid medication (tablets or injections, not creams)
Generally feeling unwell
Unexplained weight loss
Persisting severe restriction of movements in all directions
Cauda equina syndrome/widespread neurological symptoms and signs
Progressive weakness in the legs or gait disturbance
Loss of feeling in the legs / trunk
Inflammatory disorders (ankylosing spondylitis, rheumatism and related disorders)
Peripheral joint involvement
For simple musculoskeletal LBP in the absence of red flag symptoms there is no need for specific investigations such as MRI scans, blood test or even x-rays provided the symptoms improve and there is no progression. In patients with red flag symptoms, an MRI scan and a referral to a specialist should be considered as soon as possible. In case of severe or persistent/ worsening LBP simple x-rays and MRI scans can be helpful. Depending on the suspected underlying cause, x-rays, CT scans, bone scans or blood test may also be indicated.