Decompression is most commonly used to refer to a surgical procedure to alleviate pain caused by a pinched nerve (neural impingement, compressed nerve) in the spine. A pinched nerve can be caused by conditions such as spinal stenosis, herniated disc and spondylolisthesis.
In the procedure, a portion of the vertebral body and vertebral disc material is removed to relieve pressure on the nerve root by giving it more space and providing an environment conducive to healing.
Decompression can be performed as either a microdiscectomy (microdecompression) or laminectomy (open decompression). After a decompression surgery, pain may actually be worse since operating around the nerve roots may cause some increased inflammation in the area and nerve roots may need time to heal.