Shoulder Pain: When to See a Doctor and What's Causing It

When Shoulder Pain Is a Medical Emergency

Some shoulder pain signals a life-threatening event. Call emergency services now if shoulder pain appears alongside chest pressure, shortness of breath, sweating, or pain radiating down the left arm. These are classic signs of acute myocardial infarction, and referred shoulder pain is well-documented in the cardiac literature. The American Heart Association notes that atypical presentations, including isolated shoulder or jaw pain, account for a meaningful proportion of missed MI diagnoses [1].

Cardiac and Vascular Causes

Acute coronary syndrome can present as left shoulder ache with no chest pain at all, particularly in women and people with diabetes. A 2019 analysis in JAMA (N=1,253,920 acute MI admissions) found that women were 7% less likely than men to present with classic chest pain, and shoulder or back pain was among the most common atypical complaints [2]. If you have cardiovascular risk factors and new shoulder pain without a mechanical explanation, cardiac causes should be ruled out before musculoskeletal workup proceeds.

Trauma and Fracture

Sudden pain after a fall, collision, or dislocation demands same-day evaluation. A dislocated glenohumeral joint or proximal humerus fracture requires urgent reduction or orthopedic referral. Neurovascular compromise, including axillary nerve injury, can result in permanent deficits if the joint sits unreduced for more than a few hours [3].

Signs of Septic Arthritis

Shoulder redness, warmth, fever, and pain with any passive motion suggest septic arthritis, a joint infection requiring same-day hospital admission and intravenous antibiotics. The BMJ's clinical review of septic arthritis lists the shoulder as the third most common site after the knee and hip, with Staphylococcus aureus responsible for approximately 40% of cases [4].

What Causes Shoulder Pain? The Most Common Conditions

Shoulder pain in the general population most often originates from four anatomical structures: the rotator cuff, the subacromial bursa, the acromioclavicular joint, and the glenohumeral joint capsule. A 2018 systematic review in the British Journal of General Practice found that rotator cuff pathology accounted for 65 to 70% of all shoulder pain presentations in primary care [5].

Rotator Cuff Tendinopathy and Tears

The rotator cuff is a group of four muscles (supraspinatus, infraspinatus, teres minor, subscapularis) that stabilize the humeral head. Repetitive overhead activity, age-related degeneration, and acute trauma can produce tendinopathy or tears. Cadaveric studies show full-thickness rotator cuff tears in 30% of individuals over age 60 and in 62% of those over age 80, many of whom reported no pain at the time of death [6]. This means imaging findings must always be interpreted alongside the clinical picture.

Partial-thickness tears cause pain with overhead lifting and at night when lying on the affected shoulder. Full-thickness tears add weakness, particularly when trying to raise the arm above shoulder height.

Subacromial Impingement Syndrome

Impingement occurs when the rotator cuff tendons are compressed between the humeral head and the acromion during arm elevation. The classic "painful arc" between 60 and 120 degrees of abduction is the hallmark clinical finding. A Cochrane review of subacromial impingement treatments found that corticosteroid injection produced short-term pain relief superior to placebo (standardized mean difference 0.61) but that benefits faded by 12 weeks without adjunct physiotherapy [7].

Frozen Shoulder (Adhesive Capsulitis)

Adhesive capsulitis produces a global loss of shoulder motion, both active and passive, with no single traumatic trigger. It affects 2 to 5% of the general population and up to 20% of people with type 2 diabetes [8]. The condition typically progresses through three stages: freezing (painful, 6 weeks to 9 months), frozen (stiff but less painful, 4 to 6 months), and thawing (gradual recovery, 6 months to 2 years). The BMJ's 2015 systematic review concluded that physiotherapy and intra-articular corticosteroid injection each offer benefit in the early stages, but the natural history favors recovery in most patients within 2 to 3 years [9].

Acromioclavicular Joint Injury and Osteoarthritis

The AC joint sits at the top of the shoulder where the clavicle meets the acromion. Acute separation from a direct fall produces a visible step deformity and point tenderness at the joint line. Chronic osteoarthritis of the AC joint causes pain with cross-body adduction (reaching across the chest) and is seen on plain X-ray as joint space narrowing with osteophyte formation.

Biceps Tendon Pathology

The long head of the biceps tendon passes through the bicipital groove and can become inflamed or ruptured. Rupture at the proximal attachment produces the classic "Popeye sign," a visible bunching of the biceps muscle belly. A 2020 study in the American Journal of Sports Medicine found that non-operative management of proximal biceps tendon ruptures yielded acceptable functional outcomes in 80% of patients who were not overhead athletes [10].

Cervical Spine Referred Pain

C5 and C6 radiculopathy from cervical disc herniation or foraminal stenosis can send pain into the lateral shoulder and upper arm, mimicking rotator cuff pathology. The Spurling test (cervical compression with lateral flexion and rotation toward the affected side) has a specificity of 92 to 96% for cervical radiculopathy [11]. Clinicians should always screen the neck when shoulder strength testing is normal but pain is significant.

How Doctors Diagnose Shoulder Pain

A structured clinical assessment identifies the pain source in most cases before any imaging is ordered. The shoulder examination follows a four-step sequence: inspection, palpation, range of motion, and special tests.

Clinical Examination Tests

Several orthopedic tests carry well-established diagnostic accuracy:

• Neer's sign (passive forward flexion of the internally rotated arm): sensitivity 72%, specificity 66% for subacromial impingement [12].
• Hawkins-Kennedy test (passive internal rotation at 90 degrees of flexion): sensitivity 79%, specificity 59% [12].
• Empty Can test (resisted abduction in the scapular plane with internal rotation): sensitivity 69%, specificity 66% for supraspinatus tear [12].
• Drop Arm test (inability to lower arm slowly from 90 degrees): specificity 97% for full-thickness rotator cuff tear [12].

No single test is definitive. Clinicians combine findings with the patient's history and risk factors to set the pre-test probability before ordering imaging.

Imaging Choices

Plain X-rays identify fractures, calcific deposits, AC joint changes, and glenohumeral osteoarthritis but cannot visualize soft tissue. Ultrasound is the first-line soft-tissue study for rotator cuff evaluation, with a 2019 meta-analysis in Radiology reporting sensitivity of 91% and specificity of 85% for full-thickness tears compared with MRI as the reference standard [13]. MRI adds detail for labral pathology, bone marrow edema, and cases where ultrasound findings are inconclusive.

HealthRX Diagnostic Triage Framework for Shoulder Pain:

| Presentation | Urgency | First Step | |---|---|---| | Chest pain + left shoulder radiation | Emergency (911) | Cardiac workup | | Trauma, deformity, or neurovascular signs | Same-day ED | X-ray, orthopedic consult | | Fever + hot joint | Same-day ED | Joint aspiration, blood cultures | | Weakness + inability to raise arm | Within 1 week | Ultrasound, orthopedic referral | | Painful arc, no weakness, <2 weeks | 2-week trial PT | Reassess at 2 weeks | | Global stiffness, diabetes history | Within 2 weeks | Clinical diagnosis, consider injection | | Neck pain + normal shoulder exam | Within 2 weeks | Cervical spine X-ray, Spurling test |

Treatment Options for Shoulder Pain

Treatment depends entirely on the diagnosis. No single protocol fits all shoulder conditions. The American Academy of Orthopaedic Surgeons (AAOS) guidelines recommend a structured stepwise approach beginning with non-operative care for most rotator cuff and impingement presentations [14].

Physical Therapy

Physical therapy is the most evidence-supported first-line treatment for the majority of shoulder conditions. A randomized controlled trial published in the BMJ (N=90) found that a 12-week supervised exercise program produced equivalent pain and function outcomes to arthroscopic surgery for rotator cuff impingement at both 1 year and 5 years of follow-up [15]. The exercise program included progressive rotator cuff strengthening, scapular stabilization, and posterior capsule stretching.

The AAOS clinical practice guideline for rotator cuff pathology (2019) assigns a moderate-strength recommendation to physical therapy as initial management for symptomatic, nontraumatic, full-thickness rotator cuff tears in patients who are not surgical candidates or who prefer non-operative care [14].

NSAIDs and Analgesics

Non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (400 to 600 mg three times daily with food) or naproxen sodium (220 to 440 mg twice daily) reduce inflammation and pain in the short term. A Cochrane review of NSAIDs for shoulder pain found moderate-quality evidence of benefit over placebo for short-term pain relief (mean difference 1.2 points on a 10-point scale), though effect sizes are modest and GI risks must be considered for prolonged use [16].

Corticosteroid Injection

Subacromial corticosteroid injection provides faster pain relief than physiotherapy alone in the first 6 weeks, making it useful when pain is severe enough to prevent participation in rehabilitation. The most studied regimen uses triamcinolone acetonide 40 mg in 5 to 8 mL of 1% lidocaine injected under ultrasound guidance. A 2021 network meta-analysis in JAMA compared nine treatments for subacromial pain and found that injection combined with exercise produced the largest improvement in pain and function at 12 weeks compared with either treatment alone [17].

Repeated injections carry risks. Current guidelines recommend no more than three injections per year in the same joint, as cadaveric studies have shown tendon fiber disruption with frequent corticosteroid exposure [14].

Hydrodistension for Frozen Shoulder

Intra-articular hydrodistension (injecting saline, corticosteroid, and local anesthetic to distend the contracted capsule) accelerates recovery in adhesive capsulitis. A randomized trial in the Lancet (N=219) found hydrodistension plus physiotherapy superior to physiotherapy alone at 6 weeks (Oxford Shoulder Score difference: 5.2 points, P<0.001) but not at 12 months, consistent with the condition's self-limiting nature [18].

Platelet-Rich Plasma (PRP)

PRP injections for rotator cuff tendinopathy remain controversial. A 2023 systematic review and meta-analysis in the American Journal of Sports Medicine (17 RCTs, N=1,057) found that PRP reduced pain scores by a mean of 1.1 points more than saline at 3 months, a statistically significant but clinically marginal difference that did not persist at 6 months [19]. PRP may be considered for patients who have failed corticosteroid injection and physiotherapy.

Surgical Options

Surgery is reserved for cases that fail 3 to 6 months of structured non-operative care, or for acute large-to-massive traumatic rotator cuff tears in younger, active patients. Arthroscopic rotator cuff repair has a re-tear rate of 20 to 25% for medium tears and up to 40% for large tears at 2 years post-operation [20]. Patient selection, tear size, tendon tissue quality, and surgeon volume all influence outcomes.

When to See a Doctor: A Practical Timeline

"When in doubt, get it checked" is practical advice, but more specific guidance helps people make timely decisions.

See a doctor the same day or go to the emergency department if:

• Pain started during or after chest pain, shortness of breath, or palpitations.
• You sustained a fall or direct blow and the shoulder looks deformed.
• The shoulder is hot, red, and you have a fever above 38.5°C (101.3°F).
• You have sudden complete inability to raise your arm after a specific incident.
• You have severe pain after a cortisone injection (possible post-injection flare or, rarely, infection).

See a doctor within one week if:

• Shoulder weakness is new and progressive, especially if you are over 50.
• Pain wakes you from sleep most nights and is worsening, not improving.
• You have a history of cancer and develop new shoulder pain without a clear mechanical trigger.
• Numbness or tingling runs from the shoulder into the fingers.

A two-week self-management trial is reasonable if:

• Pain started with a specific activity and is mild to moderate.
• Full range of motion is preserved.
• There is no weakness, deformity, or fever.
• Over-the-counter NSAIDs are providing adequate relief.

During that two-week period, modify activity to avoid the provoking motion, apply ice for the first 48 to 72 hours (15 to 20 minutes per session), and begin gentle pendulum exercises. If pain has not improved at two weeks, book an appointment. Do not wait longer than four weeks without professional evaluation for any shoulder pain that disrupts daily activities.

Shoulder Pain in Special Populations

Athletes and Overhead Workers

Throwing athletes and workers with repetitive overhead demands face higher rates of rotator cuff pathology, SLAP (superior labrum anterior-to-posterior) tears, and internal impingement. A study in the American Journal of Sports Medicine (N=296 baseball pitchers) found that 87% of pitchers with shoulder pain on MRI had posterior superior labral fraying, compared with 24% of non-throwing controls [21]. These populations benefit from sport-specific or occupation-specific rehabilitation programs rather than generic shoulder protocols.

Older Adults

Adults over age 65 have a higher prevalence of asymptomatic rotator cuff tears, glenohumeral osteoarthritis, and AC joint degeneration. The challenge is distinguishing incidental imaging findings from the true pain source. A clinical rule of thumb: if the patient's pain pattern and physical exam findings match the imaging abnormality, treat the abnormality. If they do not match, search for another cause.

People with Diabetes

As noted above, adhesive capsulitis is significantly more common in people with type 2 diabetes. Poorly controlled blood glucose appears to accelerate capsular contracture, though the exact mechanism is not established. A cross-sectional study published in Diabetes Care (N=800) found that HbA1c above 8% was associated with a 3.6-fold increased odds of adhesive capsulitis compared with HbA1c below 7% [22]. Optimizing glycemic control should be part of the treatment plan for diabetic patients with frozen shoulder.

What to Expect at Your Appointment

Bring a clear account of three things: when the pain started, what makes it worse, and whether you have any of the red-flag symptoms listed above. Your doctor will likely perform the special tests described earlier, order imaging if warranted, and discuss a management plan.

If you are referred to physical therapy, attend consistently. A 2022 Cochrane review of adherence in musculoskeletal rehabilitation found that patients who completed at least 80% of prescribed sessions had significantly better outcomes than those who completed fewer than 50%, with a standardized mean difference of 0.74 for pain reduction [23].

If imaging shows an incidental finding (such as a small asymptomatic rotator cuff tear), ask your doctor whether it requires treatment or monitoring. The answer depends on your age, activity level, tear size, and symptom severity, not on the scan alone.

The median time from symptom onset to full recovery for rotator cuff tendinopathy managed with physiotherapy is 12 weeks, with 80% of patients reporting satisfactory outcomes at 6 months [5].