Most shoulder pain results from an injury or condition in the shoulder itself. However, sometimes shoulder pain stems from a problem in the neck.
When shoulder pain is actually coming from the neck, it is wise to seek treatment as one or more nerves running from the neck into the shoulder could be at risk.
How Shoulder Pain Feels When It’s Actually a Neck Problem
There are eight nerve roots branching from each side of the cervical spine in the neck, and they're labeled C1-C8. Nerve roots C3 through C8 all pass through a specific part of the shoulder.
If a cervical nerve root becomes compressed or irritated in the neck, it can cause pain and symptoms that radiate along the path of the nerve into the shoulder, arm and/or hand. This is medically termed cervical radiculopathy.
Radicular pain and accompanying symptoms can vary and include any or all of the following:
- Pain that feels anywhere from mild or dull to sharp, lancinating or severe
- Pain that comes and goes, or is constant and unrelenting
- Pain that stays in the same area, such as the shoulder blade, or pain that radiates along the nerve and could go from the shoulder down the arm
- Tingling that might feel like a pins-and-needles sensation, which could be in one spot or radiate through the shoulder and into the arm
- Weakness or numbness in the shoulder and/or arm, which could be constant or sporadic
Some research indicates that if shoulder pain symptoms tend to develop with the following pattern:
- C5 radiculopathy tends to lead to pain in the upper shoulder near the neck and could either be sharp pain on the surface or a deep, achy pain
- C6 radiculopathy would be more on the outer shoulder and likely a pain that feels closer to skin level
- C7 radiculopathy would be the inner part of the shoulder closer to the spine and would likely have pain that feels surface-level rather than deep
- C8 radiculopathy, which is less common than the others, would be the lower shoulder and could have pain that is either sharp on the surface or deep and achy.1
Symptoms may vary from the above depending on the underlying pathology, as well as an individual's unique anatomy and perception of pain. Most commonly, cervical radiculopathy is experienced on only one side of the body.
Common Causes of Radicular Pain in the Shoulder
Several common neck problems can cause symptoms of cervical radiculopathy, including:
- Cervical degenerative disc disease. The intervertebral discs between the vertebrae lose hydration over time. When a disc loses enough hydration it becomes thinner and less able to do its job, potentially producing pain and possibly irritating or pressuring on the nearby nerve root.
- Cervical herniated disc. Each intervertebral disc contains a hard outer layer and soft inner layer. If the outer layer gets a tear that allows the inner gel to leak out, that can inflame and/or irritate the nearby nerve root.
- Cervical osteoarthritis. When a facet joint in the neck becomes arthritic, the inflammation and excess bone growth can alter the joint’s size and spacing, which could result in a nerve root being irritated or impinged.
- Cervical foraminal stenosis. This condition occurs when the nerve root becomes compressed while going through the foramen—a small hole in the bony vertebral construct. The narrowing of the foramen can happen in various ways, such by the overgrowth of bone spurs or by a herniated disc.
This is not a complete list of conditions that can cause radicular pain in the shoulder. For instance, one of many less common possibilities could be a tumor growing in the cervical spine that pushes against a nerve root.
When to See a Doctor
If shoulder pain persists or if range of motion is affected, then a doctor should be consulted.
If cervical radiculopathy is suspected, with radiating pain, tingling, weakness, or numbness, then it’s important to see a doctor sooner rather than later in order to start treatment. If the condition causing cervical radiculopathy goes untreated and gets worse, it is possible—in some cases—for permanent nerve damage or neuropathy to occur.