Shoulder Joint Pain: Possible Causes

The shoulder joint is the most mobile in the body, and the price of this freedom is vulnerability: the bony support is small, and the arm is held mainly by soft tissues. We explain where shoulder pain comes from, how problems of the joint, tendons and nerves differ, and when it is time to see a doctor.

What the shoulder joint consists of and why it is so vulnerable

The shoulder connects three bones: the clavicle, the scapula and the humerus. The head of the humerus is a ball, the glenoid cavity of the scapula is a shallow cup, and along its edge runs the cartilaginous labrum, which increases the support area and cushions impacts. The ball is larger than the cup, so the joint is held not by bones but by muscles, tendons and ligaments.

The shoulder joint has no true ligaments — the capsule is reinforced by muscle tendons. It is a lever with a short support arm: movements are wide, and the load on soft tissues is high. Flexion and abduction go only up to shoulder level; beyond that, the scapula and the entire shoulder girdle work. Because of this instability, the shoulder is easily injured, and dislocations are common.

Main causes of shoulder pain

The doctor starts from when it hurts. Pain and stiffness that persist for months and years are the picture of a "frozen" shoulder or arthritis, osteoarthritis or rheumatoid. Pain that worsens when using the arm points to tendinitis, bursitis, impingement. Pain exactly at the top of the shoulder, where the clavicle and the joint meet, occurs with problems of the acromioclavicular joint: dislocation, stretched or torn ligaments.

Common shoulder problems:

• sprains and strains;
• dislocations and separations of the joint;
• tendinitis and bursitis;
• rotator cuff tear and "frozen" shoulder;
• fractures, including of the clavicle, and arthritis.

Tingling, numbness and weakness in the arm

Tingling, numbness and weakness in the arm can be signs of joint instability, sometimes associated with hypermobility. The doctor determines the cause by examination and tests.

Tingling that does not go away, and loss of sensation in the arm or shoulder, are a reason to get help urgently rather than wait two weeks.

Pain in the right and left shoulder: is there a difference

In reference books, the causes of shoulder pain are not divided into right and left — the list is the same. Pain in the scapula and shoulder on the right is assessed the same way as on the left: they look at the connection with movement, the shape of the joint, swelling and sensation.

One alarming sign is related to sides: severe pain in both shoulders at once requires an urgent consultation.

The connection of pain with movement and its duration

If pain sharply intensifies when moving the arm or does not go away for months, the doctor determines the cause: by examination and tests he decides whether further investigation is needed. Sudden very severe pain, when it is difficult or impossible to move the arm, is assessed separately: this occurs with dislocation, fracture or tendon rupture. Recovery can take six months or longer, so the count is kept from the time point: if there has been no improvement within two weeks, the doctor then investigates further.

When shoulder pain requires seeing a doctor

The threshold is simple: the pain increases or does not improve within two weeks, and it is very difficult to move the arm or shoulder. Diagnosis begins with history-taking and examination; if necessary, imaging is prescribed — X-ray, MRI or ultrasound. Treatment depends on the cause and is selected after examination and tests. Self-diagnosis is a poor helper: similar pain leads to different diagnoses.

Shoulder pain by itself is not a reason to call an ambulance; 103 or 112 — if the pain arose suddenly and is very severe, the arm does not move, the shoulder or arm has changed shape or is severely swollen, or the pain appeared after a fall or accident.

This material is for reference: it explains the mechanics of pain but does not replace a doctor's consultation, who will examine the shoulder and name the cause.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer