Shoulder Pain — Causes, Diagnosis, and Treatment

Author: Dr. Zeljko Kojadinovic, MD, PhD – Neurosurgeon and Pain Management Specialist

Last medically reviewed: June 10, 2026

Shoulder pain affects up to one in five adults at some point in their lives and is one of the most common musculoskeletal complaints seen in primary care.
It occurs slightly more often in women over 40 and in people with repetitive overhead activities, such as manual workers, athletes, and office employees who spend long hours at a computer.
Because the shoulder joint is the most mobile joint in the body, it depends on a complex system of muscles, tendons, and stabilizing structures. Pain may come from any of these local tissues — or be referred from the neck and upper thoracic region. Identifying the exact pain generator is therefore essential before planning treatment.

Common Causes of Shoulder Pain

Typical causes of shoulder pain include inflammation or irritation of:

• Long head of the biceps tendon — the most frequent source of anterior shoulder pain, responsible for 25–35% of chronic cases in outpatient settings.
  Inflammation within the bicipital groove (tenosynovitis) often coexists with nearby bursal irritation and causes localized tenderness and pain during flexion or supination.
• Subacromial / subdeltoid bursa (bursitis) — present in about 20–30% of patients. These bursae communicate with each other in most patients. It usually develops secondarily, as a reaction to mechanical overload or inflammation of the biceps or supraspinatus tendons.
  It produces lateral shoulder pain and night pain, often relieved after ultrasound-guided corticosteroid injection.
• Supraspinatus and rotator cuff tendinopathy — seen in roughly 15–25% of patients, frequently accompanying the biceps-bursa complex rather than existing alone.
  In younger patients, shoulder pain usually results from an acute injury causing a partial or complete tear of the supraspinatus tendon. In older adults, pain is more often due to chronic tendon degeneration (tendinopathy or tendinitis), frequently accompanied by subacromial bursitis rather than a true tear.
• Acromioclavicular (AC) joint degeneration or micro-instability — accounts for 10–15% of chronic shoulder pain, producing localized pain on top of the shoulder and discomfort on cross-arm adduction.
• Labral or capsular lesions — explain 5–10% of cases, mostly in younger or athletic individuals exposed to repetitive overhead activity.

Pain may also originate from the cervical spine or peripheral nerve irritation, which should always be considered when shoulder imaging appears inconclusive. For that reason, every case should be clinically evaluated to distinguish between true shoulder pathology and referred pain.

Image: Anatomical structures of shoulder which are the most usual cause of the shoulder pain.

The reported frequency of shoulder pain causes varies widely across studies — sometimes showing rotator cuff tendinopathy as the leading diagnosis, and in other reports highlighting biceps or bursal inflammation.
This variation reflects differences in study populations and clinical settings:

• Orthopedic surgical studies mostly include patients who failed conservative therapy or required surgery — therefore, they overrepresent rotator cuff tears and labral lesions.
• Primary care and pain-clinic studies include the full spectrum of patients — from mild overload and posture-related dysfunctions to chronic myofascial pain — where biceps tenosynovitis and subacromial bursitis are the most frequent findings.
• Imaging-based surveys (MRI or ultrasound screening) often report structural changes in asymptomatic individuals, which inflates the apparent prevalence of rotator cuff pathology.

Symptoms in Shoulder Pain

Symptoms depend on which structure around the shoulder is affected.
When the long head of the biceps tendon is inflamed, pain is usually felt at the front of the shoulder, sometimes radiating toward the upper arm. It worsens during lifting, carrying, or turning the palm upward (supination). Pressing on the bicipital groove often provokes sharp tenderness, and some patients report a sense of “clicking” in the front of the joint.

If the subacromial or subdeltoid bursa is inflamed (bursitis), pain typically appears on the outer side of the shoulder and increases when the arm is raised or during the night while lying on the affected side. It may feel like a dull ache spreading toward the deltoid region. Relief after a corticosteroid injection or rest is common.

In supraspinatus or rotator cuff tendinopathy, pain occurs with overhead activities, such as reaching for an object or dressing. Younger patients may recall a sudden injury, while older adults usually experience a gradual onset of aching and weakness. Movements like lifting the arm to the side or above the head become painful or limited.

When the acromioclavicular (AC) joint is affected, pain is most prominent on top of the shoulder, especially during cross-arm motion or when lying directly on that area. Swelling or tenderness at the AC joint may also be present.

Labral or capsular injuries cause deep, sharp pain inside the shoulder, sometimes accompanied by catching or clicking inside the joint, or a sense of instability, particularly in athletes or those performing repetitive overhead movements.

Finally, referred pain from the neck or peripheral nerves may mimic shoulder pathology. Such pain is often associated with neck stiffness, tingling, or radiating discomfort into the arm, while shoulder movements themselves remain relatively preserved.

Diagnostic Evaluation — Why Imaging Alone Is Not Enough

The first step in diagnosis is to identify which specific structure is responsible for the pain.
A common mistake is to rely too heavily on X-ray or MRI findings. In many patients, X-rays appear completely normal — or show degenerative changes that are unrelated to the actual pain source.

A correct diagnosis relies on:
• a detailed physical examination with specific shoulder function tests,
• ultrasound evaluation of soft tissues, tendons, and surrounding nerves and vessels,
• and, when necessary, small diagnostic injections that confirm the true pain generator.

Ultrasound is particularly valuable because it allows real-time visualization of tendon motion, inflammation, and local vascular changes — making it both a diagnostic and interventional tool.

Treatment of Shoulder Pain

Most shoulder pain can be effectively treated without surgery.
Management typically progresses through several stages:

• Medication and local therapy — short courses of anti-inflammatory drugs, combined with targeted local injections into or around the painful structure (usually long-acting corticosteroid suspensions that release gradually over 2-3 weeks and reduce inflammation).

• Physiotherapy — once pain is controlled, guided exercises help restore motion and strengthen the rotator cuff and scapular muscles.

• Ultrasound-guided interventions — such as lavage of calcium deposits or hydrodistension for frozen shoulder, often provide rapid relief and help avoid surgery.

• Arthroscopic and surgical procedures — indicated when pain persists despite full conservative care, including: arthroscopic decompression, tendon repair, removal of calcium deposits, or capsular release. Shoulder replacement (arthroplasty) is rarely required except in advanced degenerative disease.

Online pain consultation for regional pain in detail

Schematic explanation of the video consultation for regional pain

Answers to questions about the process and success of video consultations for regional pain

There are several common reasons for poor therapeutic outcomes in the treatment of chronic pain, which are often seen in patients with regional pain.

Artificial intelligence can also support the process by analyzing complex pain syndromes in regional pain syndrome, but clinical expertise remains essential.

Why Shoulder Pain May Persist Despite Treatment

This is a common question among patients who have already tried medication, injections, or physiotherapy — but continue to experience pain.

In many cases, treatment does not fail because the methods themselves are ineffective, but because the true pain generator has not been precisely identified. Imaging findings may show structural changes such as tendon degeneration or partial tears, yet these do not always correspond to the actual source of pain.

Even when the primary cause is correctly treated, pain can persist if additional contributing factors — such as mechanical overload, poor shoulder mechanics, muscle imbalance, or systemic influences — are not recognized and addressed. These factors can maintain irritation and prevent full recovery despite otherwise appropriate therapy.

Treatment of Contributing Factors in Shoulder Pain

Effective treatment of shoulder pain always begins with identifying the primary pain generator — the specific structure responsible for symptoms (such as the long head of the biceps tendon, subacromial bursa, rotator cuff, or AC joint).

However, in many patients, pain persists not only because of the local problem, but because additional contributing factors are not recognized or adequately addressed. These factors rarely act as the sole cause of pain, but they can maintain irritation, delay recovery, and reduce the effectiveness of otherwise appropriate treatment.

For that reason, successful management of shoulder pain requires not only treating the primary structure, but also understanding the broader mechanical and systemic context.

What contributing factors may play a role in shoulder pain?

• Repetitive overhead activity and mechanical overload — Frequent reaching, lifting, sports, or prolonged work with the arms elevated can continuously irritate the same tendon or bursa. This is usually recognized through patient history and movement testing, and improved by correcting activity patterns and load.
• Posture and scapular mechanics — Forward shoulder position and poor coordination of scapular stabilizing muscles alter shoulder biomechanics and increase stress on the rotator cuff and biceps tendon. Clinical examination typically reveals these patterns, and targeted physiotherapy helps restore balance.
• Muscle imbalance and reduced shoulder stability — Weakness of the rotator cuff or scapular muscles leads to inefficient movement and overload of specific structures. Functional testing helps identify this, and guided exercises are a key part of recovery.
• Metabolic factors, pro-inflammatory diet and low-grade inflammation — Obesity, insulin resistance, and chronic inflammation can increase pain sensitivity and slow tissue healing. These factors are often identified through clinical context and basic laboratory testing.
• Nutritional deficiencies — Low levels of vitamin D, vitamin B12, or other micronutrients may impair recovery and contribute to persistent pain. When suspected, simple blood tests can confirm the diagnosis and guide correction.
• Sleep disturbances and night pain cycle — Shoulder pain often worsens at night, and poor sleep further increases pain sensitivity. Addressing sleep quality and nighttime positioning can be an important part of treatment.
• Central sensitization — In some patients, the nervous system becomes more sensitive over time, amplifying pain even when local tissue irritation is relatively mild. This is recognized clinically and requires a broader, multimodal treatment approach.
• Stress and reduced activity due to pain — Pain often leads to avoidance of movement, resulting in loss of strength and further instability of the shoulder. Gradual return to controlled movement is essential to break this cycle.
• Medications and previous treatments — Certain medications such as statins, long-term use of pain medications, corticosteroids, or medications that cause excessive sedation may contribute to muscle or tendon-related pain, reduce tissue quality, or alter pain perception. Previous treatments, including repeated injections or incomplete rehabilitation, may also maintain symptoms if the underlying mechanism was not fully addressed.
• Other medical conditions and comorbidities — Conditions such as autoimmune diseases, thyroid disorders, diabetes, or chronic inflammatory states may increase pain sensitivity, affect tendon and joint structures, and reduce the response to otherwise appropriate treatment.
• Vitamin-related factors — Both deficiencies and excesses of certain vitamins (particularly vitamin B6) may contribute to nerve-related symptoms, burning pain, or altered sensitivity around the shoulder.
• Tissue quality and degeneration — Age-related changes, reduced blood supply, or repeated micro-injuries may impair tendon healing and increase vulnerability to persistent pain, even when mechanical factors are partially corrected.

Why this matters in practice

In many cases, treatment fails because the primary pain generator is not correctly identified, and therapy is directed only at contributing factors such as posture correction, exercise, or dietary changes. Conversely, even when the main structural cause (for example, a tendon or bursa) is treated, failure to recognize and address contributing factors often leads to only partial or temporary improvement. The most effective approach is a carefully selected combination of treatment that addresses both the primary pain generator and the contributing mechanical, functional, and systemic factors. In contrast, an inadequate or incomplete combination — even when it includes individually effective methods — is a common reason for suboptimal or short-lasting results. This approach significantly increases the likelihood of long-term improvement and reduces the need for repeated injections or surgery.

In practice, many patients try to address these contributing factors on their own — for example by improving posture, starting exercise programs, following an anti-inflammatory diet, using supplements such as vitamin D, magnesium, or joint-support products like glucosamine and chondroitin, or applying methods such as kinesio taping.

While these approaches can be helpful in selected cases, they rarely lead to lasting improvement if the primary pain generator is not clearly identified and treated. On the other hand, even well-targeted medical treatment may fail if all contributing factors are not recognized and corrected.

Many patients reading this recognize that they have already tried one part of this approach — but not the complete strategy. This is one of the most common reasons why otherwise well-treated shoulder pain becomes chronic.

Prognosis and Long-Term Outlook for Shoulder Pain

The majority of patients with persistent shoulder pain experience significant or complete relief once the true pain source is identified and treated with a combination of targeted medication and image-guided therapy.
In many cases, surgery can be completely avoided.
Even in chronic conditions, maintaining pain control for six consecutive weeks strongly predicts long-term improvement and stable shoulder function.

FAQ About Persistent Shoulder Pain