Although upper back pain is not a very common spinal disorder, it can cause significant discomfort and pain when it does occur. The most common causes of upper back pain are muscular irritation (myofascial pain) and joint dysfunction.
There can be an injury to a disc in the upper back (such as a thoracic herniated disc or degenerated disc) that causes upper back pain, but such injuries are very rare.
It is important to note that the thoracic spine (also called upper back, middle back, or mid-back) is very different in form and function than the cervical spine (neck) or the lumbar spine (lower back). While the neck and lower back are designed to provide us with mobility, the thoracic spine is designed to be very strong and stable to allow us to stand upright and to protect the vital internal organs in the chest. Because this section of the spinal column has a great deal of stability and only limited movement, there is generally little risk of injury or degeneration over time in the upper back.
The word "thoracic" means pertaining to the chest, and the thoracic spine (also called the upper back or mid-back) is the portion of the spinal column that corresponds to the chest area (Figure 1).
Because there is little motion and a great deal of stability throughout the upper back (thoracic spine), this section of the spine does not tend to develop common spinal disorders, such as a herniated disc, spinal stenosis, degenerative disc disease, or spinal instability. These conditions can cause upper back pain but are exceedingly rare in the upper back.
Because of this stability and lack of motion, in most cases anatomic causes of upper back pain cannot be found, and an MRI scan or CT scan will rarely image an anatomic problem that is amenable to any sort of surgical solution for the upper back pain.