Blood tests that may help doctors to distinguish mechanical from medical low back pain include blood chemistries, complete blood count (CBC), C-Reactive protein (CRP), and erythrocyte sedimentation rate (ESR).
When a patient presents in a diagnostic medical office for the complain of back pain, the doctor may consider among many possible causes. The doctor may consider whether the patient has pain because of a short term injury, degenerative processes in their spine, or possibly as a result of diseases. In some cases, the nerves of the spine are affected by muscle tightness and herniated discs. In other cases, the spinal nerves and the nerves of the peripheral nervous system become directly damaged due to diseases such as multiple sclerosis. Diseases such as these may be confirmed or ruled our through blood testing. In many cases, degenerative conditions in the spine involve osteoarthritis of the facet joints and degenerative disc disease of the cushions between the vertebral bones. On other cases, the soft tissues of the spine may be affected by systemic diseases such as rheumatoid arthritis and ankylosing spondylitis. Systemic diseases such as these may also be confirmed or ruled out by blood tests. Let's take a look at the type of blood tests associated with back pain diagnostics.
Laboratory tests are rarely needed in back pain diagnostics because most patients have low back pain. However, doctors may observe some red flags that indicate a systemic disease may be behind the patient's pain symptoms. Tests used for identifying abnormalities associated with medical back pain include blood chemistries, complete blood count (CBC), C-Reactive protein (CRP), and erythrocyte sedimentation rate (ESR). Medical back pain is pain that is disease related and not associated with structural problems with the spine and musculoskeletal system.
Erythrocyte sedimentation rate (ESR): Erythrocytes are our red blood cells. These are the cells within our blood which carry oxygen and carbon dioxide from the tissues of our body. For this test, a technician draws a sample of your blood. Since the red blood cells are heavier than the other clear components of your blood, they will eventually settle to the bottom of the tube in which the sample was collected into. The lab tech will record the time that it took the red blood cells to settle to the bottom. Positive results for the ESR, also known as the sed rate test, occur then the red blood cells fall at a slower rate than normal.
These cells may fall at a slower rate than normal due to inflammation in the body. Due to certain autoimmune disorders, the body's immune system somehow fails to differentiate between unwanted foreign invaders in the body and familiar healthy cells. Because of this failure, the immune system begins to attack healthy tissues. ESR is often higher in people with autoimmune conditions such as rheumatoid arthritis, lupus, Necrotizing vasculitis, Giant cell arteritis, and HLA-B27 diseases. The majority of patients with conditions such as psoriatic arthritis, reactive arthritis (Reiter's syndrome), and ankylosing spondylitis test positive for the HLA-B27 gene.
The ESR test does not definitively tell doctors what condition they have. It just points in the direction of a likely possibility of a systemic disease in the body.
C-Reactive protein (CRP): the liver in our bodies also react systemic inflammatory conditions. C-Reactive protein is produced by the liver when inflammation is present in the body. Normal CPR levels are less than 0.2mg/100ml. Levels between 1-10mg/100ml are moderate increases. Levels higher than 10mg/100ml are considered to be highly elevated. These levels remain high in chronic inflammatory states.
CPR is found within the blood, as a result of its production by the liver in response to inflammation. When cells become damaged or are dying, C-reactive proteins bind to them by attaching to phosphocholines on their surface. Certain diseases that stimulate the liver to produce CPRs include pneumococcus, cancer, cardiovascular disease, and inflammatory disease.
Complete blood count (CBC): This test measures the total count of all of the components of blood, including platelets and white and red blood cells. This test as well as blood chemistries may measure kidney and liver function to determine if the medications that patients are taking to treat their back pain are having unacceptable side effects on the body. Nonsteroidal inflammatory drugs such as Meloxicama, Naproxen, and ibuprofen are considered safe for taking for short-term use, though there are complications related to the digestive tract, liver, and kidneys when taking for long-term use.