The most common reason your shoulder hurts when you raise your arm is that soft tissue inside the joint is getting pinched or compressed as you lift. The shoulder is a tight space, and when tendons or fluid-filled cushions swell even slightly, they run out of room during overhead movements. Several conditions cause this, and the specific pattern of your pain can help narrow down what’s going on.
Shoulder Impingement: The Most Likely Cause
Shoulder impingement is the single most common explanation for pain during arm raising. It happens when the top edge of your shoulder blade squeezes the rotator cuff tendons beneath it. Your rotator cuff is a group of four muscles that connects your shoulder blade to your upper arm bone, and a small fluid-filled sac called a bursa sits between them as a cushion. When either the tendons or the bursa swell from overuse or irritation, there’s no longer enough room for everything to glide smoothly, and bone presses against soft tissue every time you lift your arm.
A hallmark of impingement is something called a “painful arc.” Pain typically kicks in when your arm is between about 60 and 120 degrees of elevation (roughly from waist height to shoulder height), then eases once your arm passes above that range. If your pain follows this pattern, impingement is a strong possibility. Overhead rotation motions, like reaching for a high shelf or throwing a ball, tend to make it worse. The pain often builds gradually over weeks rather than appearing all at once.
Rotator Cuff Tendonitis and Tears
The rotator cuff tendons can also develop problems on their own, independent of impingement. Tendonitis happens when repetitive overhead activity or heavy lifting irritates the tendon faster than it can repair itself. Micro-tears develop in the tissue, causing pain and inflammation that flares with arm raising and rotation. This is common in people who do a lot of overhead work, whether that’s painting ceilings, swimming, or lifting weights.
A partial or gradual tear feels similar to tendonitis but tends to come with noticeable weakness. You might struggle to hold your arm steady at shoulder height, or lifting a coffee cup out to the side feels harder than it should. An acute tear, caused by a sudden force like a fall or a shoulder dislocation, is different. It produces immediate, sharp pain and an obvious inability to raise or rotate the arm. If your pain started suddenly after an injury and you can barely lift your arm, that points toward a significant tear rather than simple inflammation.
Bursitis in the Shoulder
The bursa that cushions the space between your rotator cuff and shoulder blade can become inflamed on its own, a condition called subacromial bursitis. The pain can come on suddenly or build up gradually. Many people describe a dull, constant ache that sharpens into a pinching sensation when lifting the arm overhead.
Bursitis has a few distinguishing features. Sleeping on the affected shoulder often makes it significantly worse, sometimes waking you up at night. The area may feel warm or tender to even a light touch. Swelling, stiffness, and a noticeably reduced range of motion are all typical. Because the bursa sits in the same tight space as the rotator cuff tendons, bursitis and impingement frequently overlap or occur together.
Frozen Shoulder
If your shoulder pain is accompanied by a steadily worsening stiffness that makes it physically impossible to raise your arm to its full height, frozen shoulder (adhesive capsulitis) may be the cause. This condition progresses through three distinct stages over a long timeline.
The first stage, called “freezing,” lasts six weeks to nine months. Pain increases slowly, often worsening at night, and your range of motion shrinks week by week. The second stage, “frozen,” lasts two to six months. Pain may actually lessen, but your shoulder is at its stiffest, making daily tasks like getting dressed or reaching behind your back genuinely difficult. The final “thawing” stage takes six months to two years, during which motion and strength gradually return. The full cycle can take one to three years from start to finish. Frozen shoulder is more common in people with diabetes, thyroid disorders, or after a period of forced immobility like wearing a sling.
Calcium Deposits in the Tendon
Calcific tendonitis occurs when calcium crystals build up inside the rotator cuff tendons. As the deposits grow, they make the tendon bulkier, which can trigger impingement as the enlarged tendon rubs against the bone above it. The pain with arm movement can be intense, sometimes severe enough to make any shoulder use feel unbearable during a flare-up. This condition sometimes resolves on its own as the body gradually reabsorbs the calcium, but flare-ups can be unpredictable.
What Your Doctor Will Check
A physical exam for shoulder pain during arm raising typically involves a few specific movement tests. In one common test, the examiner lifts your straightened arm forward and overhead with your palm facing down, compressing the space under your shoulder blade. If this reproduces your pain, it suggests impingement. In another, the examiner bends your elbow and shoulder to 90 degrees, then rotates your arm inward across your body. Pain during this maneuver also points to impingement or rotator cuff irritation.
Your doctor will also test for weakness by having you hold your arm out in specific positions against resistance. Significant weakness, especially if you can’t hold your arm up at all, raises concern for a rotator cuff tear. Imaging like an X-ray can reveal calcium deposits or bone spurs, while an MRI gives a detailed look at the soft tissues to identify tears, inflammation, or bursitis.
How Recovery Typically Works
Most shoulder pain from impingement, bursitis, or tendonitis improves with conservative treatment. The first steps are usually rest from aggravating activities (especially overhead motions), ice, and over-the-counter anti-inflammatory medication. Physical therapy is the cornerstone of recovery, focusing on strengthening the rotator cuff muscles so they stabilize the joint better and stretching to restore range of motion.
Improvement is gradual. Most people notice meaningful progress within several weeks of consistent physical therapy, though full resolution can take two to three months or longer depending on severity. If pain persists despite months of conservative treatment, a procedure to create more space under the shoulder blade may be considered, particularly in younger or more active patients. For confirmed rotator cuff tears that cause persistent weakness and functional limitation, surgical repair becomes a more direct consideration.
When Shoulder Pain Signals Something Else
Shoulder pain that has nothing to do with the shoulder itself is rare but worth knowing about. A heart attack can cause pain that spreads to one or both shoulders, arms, the back, neck, or jaw. The key difference is context: cardiac shoulder pain typically comes with chest pressure or tightness, shortness of breath, cold sweats, nausea, lightheadedness, or a sense of dread. It doesn’t change with arm position or movement the way a musculoskeletal problem does. Women sometimes experience more subtle symptoms, like brief or sharp pain in the neck, arm, or back without obvious chest pressure. If your shoulder pain comes with any of these additional symptoms, especially chest pressure that doesn’t go away with rest, treat it as an emergency.