When upper back or shoulder pain is accompanied by numbness in the arm, it can stem from a problem in the neck or shoulder that inflames a nerve going down the arm. Some people may have worsening upper back pain and arm numbness as the day goes on, whereas others may experience worse symptoms when waking up in the morning. Here are 6 potential causes.
Cervical herniated disc
When a cervical disc herniates, inflammatory proteins can leak out of the disc and inflame nearby muscles, joints, and/or nerve roots. If a cervical nerve root becomes inflamed, radicular pain, tingling, numbness, and/or weakness may go down into the shoulder, arm, and/or hand. Especially if a disc herniates in the lower cervical spine, pain may be felt in the shoulder blade area with some numbness that could go into the arm or hand.
Foraminal stenosis
When the intervertebral foramen narrows between adjacent vertebrae, called foraminal stenosis, a nerve root can become impinged while exiting from the spinal canal. Foraminal stenosis can be caused by bone spurs (osteophytes) or other spinal degenerative processes. If the nerve root in the lower cervical spine becomes pinched or inflamed, it can potentially cause pain, tingling, numbness, and/or weakness in the shoulder, arm, hand, and/or fingers.
See Cervical Foraminal Stenosis
Stinger
A stinger typically results from trauma to the neck or shoulder, such as during a sports collision or fall. When the brachial plexus (a group of nerves that run through the shoulder and down the arm) becomes overstretched during a collision, a stinger injury can cause burning pain that starts in the neck or shoulder and goes down the arm. It may also be accompanied by some numbness or weakness in the arm or hand. While stingers usually only last a few seconds or minutes, they sometimes last days or longer.
Read more about Stinger Injuries on Sports-health.com
Thoracic outlet syndrome
Thoracic outlet syndrome (TOS) occurs when the nerves or blood vessels become compressed in the thoracic outlet, which is the area between the top rib and collarbone. This rare condition can cause pain, tingling, numbness, and/or weakness anywhere from the neck and shoulder down into the arm and hand. So it’s possible for someone with TOS to feel pain in the shoulder and numbness in the arm. Performing overhead work may exacerbate shoulder pain and arm numbness/weakness. The arm and hand may also become more easily fatigued during routine activities.
See Neck Pain from Thoracic Outlet Syndrome
Brachial neuritis
Brachial neuritis, also called Parsonage-Turner syndrome, develops when at least a part of the brachial plexus (a group of nerves that run through the shoulder and down the arm) becomes inflamed. This condition typically has sudden onset unrelated to an injury, and it can cause pain, tingling, numbness, and/or weakness anywhere along the nerve pathways from the neck, upper back, shoulder, and down into the arm and hand. Brachial neuritis typically lasts anywhere from a few hours to a few days. In rare cases, it can last much longer or become permanent.
Stress
It is well established that stress, anxiety, post-traumatic stress disorder (PTSD), and other psychological conditions can create physical symptoms that can mimic the above conditions. It is always important to consider stress as a possible source for symptoms including upper back pain and associated arm numbness.
Any type of pain that is accompanied by numbness or weakness requires a visit to the doctor. Getting an accurate diagnosis from a medical professional can help determine the most effective treatment for relief and recovery.
See The Diagnosis of Stress-Related Back Pain