It is a surprisingly difficult question to answer from the inside.
Pain sits somewhere between the base of your neck and the top of your arm. You can point at it, roughly. But whether the problem is in your neck or in your shoulder is not obvious, and plenty of people spend months treating the wrong one.
The two regions share nerve supply and sit right next to each other, which means they refer pain into overlapping territory. A neck problem can produce pain you feel entirely in your shoulder. A shoulder problem can produce aching up toward your neck.
Here is how to tell them apart, which matters because the treatments have almost nothing in common.
Start with where it actually is
Not exactly, but roughly.
Shoulder problems tend to be felt over the outer part of the upper arm, around the deltoid, sometimes extending down toward the elbow. People frequently grab the outside of their upper arm when describing it.
Neck problems tend to be felt in the neck itself, across the top of the shoulder, between the shoulder blades, or in a band running down the arm.
A useful detail. Shoulder problems rarely produce symptoms below the elbow. If you have pain, numbness or tingling in your forearm or hand, that points toward the neck rather than the shoulder.
The two questions that do most of the work
Try these at home.
First, move your neck. Look up, look down, turn each way, tilt each way. Does any of that reproduce or change your pain?
If moving your neck reliably changes your symptoms and moving your arm does not, that points to the neck.
Second, move your arm. Lift it forward, out to the side, reach behind your back, reach across your body. Does any of that reproduce or change your pain?
If moving your arm reliably changes your symptoms and moving your neck does not, that points to the shoulder.
Neither test is definitive, and together they narrow things down considerably more than most people expect.
What points toward the shoulder
Pain with specific arm movements rather than in general. Reaching overhead, reaching behind your back, lifting out to the side.
A painful arc, meaning it hurts through part of the range and eases beyond it.
Pain lying on that side at night. This is one of the more reliable indicators of a shoulder problem.
Weakness that is clearly about pain rather than the muscle failing. You can do it, it just hurts.
Difficulty with specific tasks involving the arm. Washing your hair, fastening a bra, reaching into a back seat, putting on a coat.
And no symptoms below the elbow.
What points toward the neck
Pain that changes with neck position, including when you hold your head in a certain way for a while.
Symptoms traveling down the arm in a line, particularly past the elbow.
Numbness or tingling, especially in specific fingers. Which fingers matters, because different nerves supply different territories.
Stiffness or restricted neck movement.
Pain that eases when you put your hand on top of your head. That position takes tension off the nerves in the neck, and relief in that position is quite characteristic.
Headaches, particularly starting at the base of the skull.
And symptoms that worsen with coughing or sneezing.
The test that separates them most clearly
One more, which clinicians rely on heavily.
Get somebody to lift your arm for you while you stay completely relaxed.
If your shoulder moves freely when somebody else does the work, even if it hurts to do it yourself, the restriction is not mechanical. That points away from certain shoulder problems.
If the shoulder will not move even when somebody else moves it, the restriction is in the joint itself. That points to a genuine shoulder problem, including the kind involving a stiff joint capsule.
It is not a perfect test and it is informative, particularly when stiffness rather than pain is the main complaint.
It is frequently both
Worth saying, because the article so far suggests a clean split and real life rarely offers one.
Plenty of people have a neck contributing to a shoulder problem, or a shoulder problem that has left them holding their neck differently for months.
The two also influence each other mechanically. The muscles supporting your shoulder blade attach to your neck, so a shoulder blade that is not doing its job leaves neck muscles picking up the slack. And a stiff upper back affects both.
Which is why a good assessment looks at the whole region rather than picking one and ignoring the other, and why treating only the painful spot frequently disappoints.
Why getting this right matters
Because the treatments genuinely differ.
A shoulder problem usually involves rotator cuff and shoulder blade strengthening, restoring range, and managing the loads going through the joint.
A neck related problem involves neck mobility and strengthening, sometimes specific nerve related work, and addressing the sustained positions contributing to it.
Doing rotator cuff exercises for a neck problem is not harmful. It also will not help much, and months of that is how people end up believing their problem is untreatable.
The questions worth bringing to an appointment
Where exactly is it, and can you point to it?
Does it go below the elbow?
Is there numbness or tingling, and if so where?
Does moving your neck change it?
Does moving your arm change it?
Can you lie on that side at night?
Is there anything you cannot do that you used to be able to?
And what changed in the weeks before it started?
Those eight answers get most of the way there.
When to seek medical attention
Some things need attention rather than working out which region they belong to.
Seek prompt medical assessment for true weakness rather than pain limited movement, numbness affecting both hands, clumsiness with fine tasks such as buttons or keys, dropping things, a change in your walking or balance, severe unrelenting night pain, neck or shoulder pain with fever, unexplained weight loss or night sweats, any history of cancer with new pain in this area, or symptoms following a significant fall or impact.
That cluster involving hand clumsiness, both hands, and changes in walking is particularly worth acting on, because it suggests something different from a single irritated nerve.
And seek emergency care for shoulder or arm pain accompanied by chest discomfort or pressure, breathlessness, sweating, nausea, or pain spreading into the jaw. Cardiac pain can present in the shoulder and arm, and that is not worth waiting on.
Also seek emergency care for sudden severe headache, facial drooping, slurred speech, one sided weakness, double vision or difficulty swallowing.
Get the right region treated
If you have been doing exercises for months without much change, the most likely explanation is not that the exercises were wrong. It is that they were aimed at the wrong place.
Campbell Physical Therapy offers a free discovery visit at no cost and no obligation. You will get a thorough assessment of your neck, shoulder and the upper back in between, a clear explanation of where your symptoms are actually coming from, and a plan targeting that.
If what you describe needs medical investigation, we will tell you plainly and help you get there.
