Shoulder Pain by Location: Common Causes, Symptoms, and What They Mean

Shoulder pain is not random. The location of your pain and the way your symptoms behave can serve as important diagnostic clues to the underlying problem. By understanding the source of your symptoms, you can take the appropriate steps toward getting an accurate diagnosis and effective treatment.

As a sports medicine physician in the San Francisco Bay Area, I have treated thousands of patients with shoulder pain, and the same patterns come up again and again. Certain types of pain are far more common than others, and when you match the location with the way the pain behaves, you can often narrow down the most likely diagnosis. In this article, I walk through the most common causes of shoulder pain organized by location, explain what they mean, and help you understand what to do next.

Rotator Cuff Disorders: Pain on the Outside of the Shoulder

The most common cause of shoulder pain is a rotator cuff disorder. Rotator cuff problems tend to produce pain along the outside of the upper arm, often in the deltoid region. Patients typically describe a dull ache that worsens with overhead activity, reaching behind the back, or lifting objects away from the body. One of the hallmark features is pain at night, especially when lying on the affected shoulder, which can significantly disrupt sleep.

Rotator cuff issues range from tendon irritation and inflammation — often called tendinopathy — to partial or complete tears. These conditions are extremely common. A population-based study by Yamamoto et al. found that approximately 20.7% of shoulders in the general population had full-thickness rotator cuff tears, with prevalence increasing significantly with age. Notably, nearly 17% of individuals without any shoulder symptoms also had tears on ultrasound imaging. The pain arises because the tendons become pinched or overloaded, leading to microdamage and inflammation. Over time, if the tendon fails to heal properly, it can weaken and progress from tendinopathy to a partial and then full-thickness tear.

Frozen Shoulder (Adhesive Capsulitis): Deep Aching with Progressive Stiffness

The next major cause of shoulder pain is adhesive capsulitis, commonly known as frozen shoulder. Unlike rotator cuff problems, where pain is usually worst with specific activities, frozen shoulder is characterized by both pain and a progressive loss of motion. Patients often describe a deep, aching pain throughout the shoulder joint, but what truly sets this condition apart is the stiffness. Everyday tasks like reaching overhead, fastening a bra strap, or putting on a jacket become difficult or nearly impossible.

One of the key differences between frozen shoulder and rotator cuff disorders is the pattern of restricted motion. In frozen shoulder, the loss of range of motion is global — meaning all directions of movement are limited, both when you move the arm yourself (active range of motion) and when a clinician moves it for you (passive range of motion). In contrast, rotator cuff disorders may cause weakness or limited motion, but typically only in one or two directions, such as abduction or external rotation, while other ranges remain relatively normal.

Shoulder Arthritis: Glenohumeral vs. AC Joint Osteoarthritis

While the shoulder does not develop arthritis as frequently as the knee or hip, it remains an important source of pain, particularly in older adults. There are two main types of shoulder arthritis that I see regularly in clinical practice: glenohumeral arthritis, which affects the ball-and-socket joint, and acromioclavicular (AC) joint arthritis, which affects the small joint at the top of the shoulder.

Glenohumeral Joint Arthritis

Glenohumeral arthritis typically causes a deep, aching pain felt throughout the entire shoulder joint. Patients often describe stiffness along with grinding or catching sensations during movement. Unlike frozen shoulder, the loss of motion is not truly global — it presents more as a gradual, painful restriction that worsens as the cartilage deteriorates over time. Pain is frequently aggravated by weight-bearing through the arm or repetitive overhead motions.

AC Joint Arthritis

AC joint arthritis, on the other hand, produces pain that is localized right on top of the shoulder. A classic symptom is discomfort with cross-body movements, like reaching across the body to grab a seatbelt or performing a push-up. Many patients will even point directly to the joint at the end of the collarbone when asked where it hurts. AC joint arthritis often coexists with rotator cuff disorders, which can make the diagnosis more nuanced and require careful clinical evaluation.

Labral Tears and Shoulder Instability: Deep Pain with Clicking or Catching

Another important cause of shoulder pain, especially in younger and more active individuals, is labral injury and instability. The labrum is a ring of fibrocartilage that deepens the shoulder socket and helps keep the ball of the humerus securely in place. When it tears, or when the ligaments around the joint become stretched or damaged, the shoulder can lose stability.

Patients with labral tears or instability often describe pain that feels deep inside the shoulder rather than on the surface. They may notice clicking, catching, or a sensation of the shoulder "slipping" out of place. In athletes — particularly throwers, swimmers, and overhead sport participants — this often presents as pain with overhead motions or a loss of throwing velocity. In others, it may follow a traumatic event such as a fall or shoulder dislocation.

Unlike rotator cuff or arthritis pain, which tends to be more predictable and constant, labral and instability-related pain can be intermittent and position-dependent. A classic finding is pain or apprehension when the arm is placed in an overhead and externally rotated position — similar to the motion of throwing a ball.

Biceps Tendonitis: Pain in the Front of the Shoulder

Biceps tendonitis typically presents as pain in the front of the shoulder, especially with lifting, pulling, or carrying objects. Patients often point directly to the bicipital groove at the top of the humerus, where the tendon of the long head of the biceps runs.

In most cases, biceps tendon pain is not a primary problem but rather occurs in association with other shoulder pathology, particularly rotator cuff disease or labral tears.

When the rotator cuff — especially the subscapularis or supraspinatus — is weakened or injured, the long head of the biceps takes on an added role in helping stabilize the shoulder. This extra mechanical load can irritate the tendon and produce that sharp or aching anterior shoulder pain.

Because of this close relationship, effective treatment usually involves addressing the underlying shoulder pathology rather than targeting the biceps tendon alone. Once the rotator cuff or labral issue is properly treated, the stress on the biceps tendon decreases and the pain often improves significantly.

Acute Calcific Tendonitis: Sudden, Severe Shoulder Pain Without Injury

Acute calcific tendonitis occurs when calcium deposits form within the rotator cuff tendons, most commonly the supraspinatus. While calcium deposits can sometimes sit silently in the tendon without causing any symptoms, the active process of calcium formation and resorption can trigger a sudden and extremely painful inflammatory reaction.

Patients with acute calcific tendonitis typically describe 10 out of 10 pain that comes on out of nowhere — without any preceding trauma or injury. The pain is so intense that many patients end up in the emergency room seeking relief. Unlike the more gradual onset of rotator cuff tendinopathy or arthritis, this pain strikes abruptly, is highly inflammatory in nature, and often makes it nearly impossible to move the shoulder. Even small attempts at lifting or rotating the arm can produce sharp, stabbing pain.

The good news is that this acute, formative phase is usually self-limited. The severe pain tends to last several days to a couple of weeks, after which the inflammation gradually subsides. Treatment during this phase focuses on controlling pain with anti-inflammatories, rest, and sometimes targeted injections until the episode resolves. While it can feel catastrophic in the moment, the prognosis is generally favorable, and surgery is rarely needed.

Cervical Radiculopathy: Shoulder Pain That Actually Comes from the Neck

A condition that frequently mimics true shoulder pathology is cervical radiculopathy — pain referred from the neck. In this case, the pain is not originating from the shoulder joint or its surrounding tendons at all. Instead, it is caused by a pinched or irritated nerve root in the cervical spine.

Cervical radiculopathy often produces pain that radiates from the neck into the shoulder and down the arm. Patients may also notice numbness, tingling, or weakness in specific patterns depending on which nerve root is affected. Unlike rotator cuff or arthritis pain, which is usually localized to the shoulder itself, radicular pain tends to travel in a line or band pattern and may worsen with neck movements such as looking up, turning the head, or holding the head in one position for too long.

This distinction is clinically important because treatment for cervical radiculopathy is entirely different from treatment for shoulder pathology. Managing the neck problem — whether through physical therapy, posture correction, medications, or targeted injections — is what ultimately improves the symptoms. That is why anyone with radiating pain, numbness, or weakness should be carefully evaluated to ensure the problem is not originating from the cervical spine.

Myofascial Trigger Points: Scapular and Upper Back Pain Often Mistaken for Shoulder Problems

A source of shoulder pain that is often overlooked is myofascial trigger points. Unlike structural problems inside the joint, this type of pain originates from irritated or overworked muscles around the shoulder blade and upper back — most commonly the rhomboids, trapezius, and levator scapulae.

Patients with myofascial pain typically describe a dull, aching, or sometimes burning discomfort along the scapula or upper back rather than deep in the shoulder joint itself. The pain is often focal, felt in tight "knots" or bands of muscle that are tender to the touch. Posture plays a significant role — hours of sitting at a desk, looking down at a phone, or repetitive overhead activity can overload these muscles and produce trigger points that refer pain toward the shoulder.

One of the key clinical clues is that strength and range of motion are typically normal, which helps differentiate myofascial pain from rotator cuff disease or arthritis. Treatment focuses on addressing the underlying muscle dysfunction through stretching, strengthening postural stabilizers, soft tissue release, and improving ergonomics. Once these muscles are retrained and the overload is reduced, the pain usually improves quickly.

When Should You See a Doctor for Shoulder Pain?

Understanding the location and behavior of your shoulder pain is an important first step toward identifying what may be causing it. A clinical consensus from Eubank et al. developed a standardized decision-making tool for primary care providers to improve the accuracy of shoulder pain diagnosis, emphasizing the importance of matching pain location, movement patterns, and physical exam findings to narrow the differential. If your shoulder pain persists beyond a few weeks, wakes you at night, involves weakness or numbness, or came on suddenly without injury, it is worth seeking a thorough evaluation from a musculoskeletal specialist.

In my practice, I use diagnostic ultrasound as part of the physical exam to visualize the shoulder in real time, which allows for rapid and accurate diagnosis at the point of care. Whether the issue is a rotator cuff tear, frozen shoulder, arthritis, or something else entirely, an accurate diagnosis is the foundation for effective treatment.

Schedule a Consultation

If you are experiencing persistent shoulder pain and want to get an accurate diagnosis and personalized treatment plan, I offer comprehensive evaluations including diagnostic ultrasound and a full range of non-surgical treatment options. Schedule an appointment today.

References

1. Yamamoto A, Takagishi K, Osawa T, et al. Prevalence and risk factors of a rotator cuff tear in the general population. J Shoulder Elbow Surg. 2010;19(1):116-120. doi:10.1016/j.jse.2009.04.006

2. Eubank BHF, Lackey SW, Slomp M, Werle JR, Kuntze C, Sheps DM. Consensus for a primary care clinical decision-making tool for assessing, diagnosing, and managing shoulder pain. BMC Fam Pract. 2021;22(1):201. doi:10.1186/s12875-021-01544-3

Author: Dr. Jeffrey Peng, MD — Board-Certified Sports Medicine Physician, San Francisco Bay Area

Published: March 1, 2025 | Last Updated: March 1, 2025