Shoulder bursitis is inflammation of a small, fluid-filled sac called the subacromial bursa that sits between the bony tip of your shoulder and the tendons beneath it. This sac normally acts as a cushion, reducing friction when you raise or rotate your arm. When it becomes irritated and swollen, the result is pain that typically worsens with overhead movements and can make everyday tasks like reaching into a cabinet or putting on a jacket surprisingly difficult.
What the Bursa Does and Why It Matters
Your shoulder joint has more range of motion than any other joint in your body, and that flexibility comes at a cost: the soft tissues inside the joint take a beating. The subacromial bursa sits just below the bony projection at the top of your shoulder blade and above the rotator cuff tendon. Together with a second nearby bursa, it prevents the tendon from grinding against bone every time you lift your arm. When this thin sac swells with excess fluid, it gets pinched in the narrow space between bone and tendon, creating a cycle of compression, irritation, and more swelling.
Common Causes and Risk Factors
Overuse is the most frequent trigger. Repetitive overhead motions, especially forceful ones like swinging a hammer, throwing a ball, or painting a ceiling, irritate the bursa over time. Sports injuries and sudden strain can also set off an acute episode. Occupations that load the shoulders heavily carry the highest risk: painters, carpenters, landscapers, plumbers, and warehouse workers all show up disproportionately in bursitis statistics.
You don’t have to be an athlete or manual laborer to develop it, though. Several systemic conditions raise your baseline risk by promoting inflammation throughout the body. These include rheumatoid arthritis, gout, psoriatic arthritis, diabetes, chronic kidney disease, and thyroid disorders. A direct blow to the shoulder, such as a fall, can also trigger bursitis without any repetitive component.
What Shoulder Bursitis Feels Like
The hallmark symptom is pain on the outer or top part of the shoulder that flares when you lift your arm away from your body, particularly in the mid-range of motion (roughly 60 to 120 degrees). This is sometimes called a “painful arc” because the pain peaks in the middle of the movement and eases once your arm is fully raised or back at your side. Reaching behind your back, sleeping on the affected shoulder, and pushing or pulling heavy objects are common pain triggers.
Night pain is a frequent complaint. Many people find that lying on the affected side compresses the inflamed bursa, making it hard to find a comfortable sleeping position. Over time, the pain can cause you to guard the shoulder and move it less, which leads to stiffness and gradual loss of range of motion.
Bursitis vs. Rotator Cuff Problems
One thing that confuses a lot of people is how much overlap exists between shoulder bursitis, rotator cuff tendinitis, and impingement syndrome. Johns Hopkins Medicine notes that these terms are often used interchangeably because they describe the same basic problem: pain and swelling involving the rotator cuff tendons and the surrounding bursa. In practice, bursitis rarely exists in complete isolation. The bursa and tendon sit so close together that irritation of one almost always involves the other.
A full-thickness rotator cuff tear is a different situation. With a tear, you may notice significant weakness when trying to lift your arm or hold it steady against resistance. Bursitis alone causes pain but typically preserves your strength once the initial discomfort is managed. That distinction matters because tears sometimes require surgical repair, while bursitis almost always responds to nonsurgical treatment.
How It’s Diagnosed
Most cases are diagnosed through a medical history and physical exam. Your doctor will press on specific spots around your shoulder to locate the source of pain and ask you to move your arm in various directions. This is usually enough to identify the problem.
Imaging comes into play when the diagnosis is uncertain or the pain doesn’t respond to initial treatment. X-rays can’t confirm bursitis directly, but they help rule out other causes like a fracture or bone spur. Ultrasound or MRI can show fluid in the bursa and reveal whether the rotator cuff tendon is also damaged. In some cases, blood tests or fluid drawn from the bursa help determine whether an infection or a condition like gout is driving the inflammation.
Treatment: What to Expect
The first line of treatment is straightforward: rest the shoulder from the activity that triggered the problem, apply ice, and use over-the-counter anti-inflammatory medications like ibuprofen or naproxen to bring down swelling and pain. Acetaminophen can help with pain as well, though it doesn’t address inflammation directly. Topical anti-inflammatory creams rubbed over the sore area are another option.
Even while you’re resting, gentle range-of-motion exercises are important. Moving the joint through its full range each day prevents the stiffness that can set in quickly when you stop using a painful shoulder. As the pain decreases, strengthening exercises for the muscles around the joint become the focus. Physical therapy is often recommended to guide this progression and correct any movement patterns that contributed to the problem in the first place.
If conservative measures aren’t enough, a corticosteroid injection into the subacromial space can provide meaningful relief. In one study of patients with subacromial impingement, pain scores dropped from an average of 5.9 out of 10 before the injection to 2.5 at two weeks. About two-thirds of patients experienced a clinically significant reduction in pain at the two-week mark, and that number rose to 78% by six months. Improvements in shoulder function and quality of life followed a similar pattern. Injections aren’t a permanent fix for everyone, but they can break the pain cycle long enough to make physical therapy productive.
When Surgery Becomes an Option
Surgery is reserved for cases that don’t improve after at least four to six months of consistent nonsurgical treatment. The most common procedure is subacromial decompression, where the surgeon removes inflamed bursal tissue and shaves down any bone spurs that are narrowing the space. This is typically done arthroscopically through small incisions, which means a shorter recovery compared to open surgery. Most people return to normal activities within a few months, though full recovery can take longer depending on the extent of the procedure and how diligently rehabilitation is followed.
Exercises to Prevent Recurrence
Once the acute inflammation resolves, targeted stretching and strengthening help keep the problem from coming back. Two stretches are particularly useful:
- Posterior shoulder stretch: Hold the elbow of your affected arm with the opposite hand and gently pull it across your body. You should feel a stretch across the back of the shoulder. Hold for 15 to 30 seconds and repeat two to four times.
- Up-the-back stretch: Place the hand of the affected arm in your back pocket, palm facing outward, and let it rest there. For a deeper stretch, use the opposite hand to gently pull the wrist upward behind your back. A towel draped over the opposite shoulder can help you gradually increase the range. Hold for 15 to 30 seconds, two to four times.
Strengthening the muscles that stabilize your shoulder blade is equally important because these muscles control how your shoulder moves during overhead activity. When they’re weak, the subacromial space narrows more than it should with each arm raise, setting the stage for repeated irritation. A physical therapist can tailor a strengthening program to your specific weaknesses, but the general goal is building endurance in the muscles that keep the shoulder blade anchored against the rib cage during movement.