The shoulder is a mobile structure with a versatile range of motion. Because of its mobility, it is vulnerable to various injuries that may cause pain and restrict movement.

Shoulder pain becomes increasingly common as you age. This is because the soft tissues around the shoulder tend to degenerate with age. Damage to the shoulder might also result from manual labor, sports, or even with repetitive movement. Certain diseases can also bring about pain that radiates to the shoulder.

 

Shoulder Anatomy

The shoulder has three main bones:

  • Upper arm bone (humerus)
  • Shoulder blade (scapula)
  • Collarbone (clavicle)

The shoulder blades (scapula) are the triangular bones on the back of the shoulders. It joins the upper arm bone (humerus) to the collarbone (clavicle). There are three groups of muscles attached to it.

The rotator cuff is a cluster of four muscles and tendons that keep the upper arm bone (humerus) firmly in the shoulder blade (scapula). It stabilizes and confers motion to the shoulder joint.

The main joints in the shoulder are acromioclavicular joint and shoulder joint (glenohumeral joint). The glenohumeral joint (shoulder joint) is a ball-and-socket joint that comprises the outer edge of the scapula and the top part of the humerus. Above the primary shoulder joint, there’s a smaller joint known as the acromioclavicular joint which connects the clavicle to the uppermost part of the scapula; it helps the shoulder joint to move through its full range.

The biceps tendons attach the shoulder bone to the biceps muscle. It has two heads, one longer than the other. It is predominantly the long-head of the biceps that becomes susceptible to injury.

The bones, ligaments, and tendons are encased in a capsule. Within the capsule is synovium fluid, which lubricates the joints and keeps the cartilage healthy. Also cushioning the joints is a protective layer of cartilage, which is a tough, rubbery substance between the ends of bones that allow them to glide smoothly against each other. The bursae are small, fluid-filled sacs in between the rotator cuff and the acromion (the bone on top of the shoulder).

 

Causes of shoulder pain

Most causes of shoulder pain fall into four major categories:

  • Tendon inflammation (tendinitis or bursitis) or tendon tear
  • Arthritis
  • Instability
  • Fracture

Rotator cuff tendinitis and tendinopathy

Rotator cuff tendonitis is a prevalent cause of shoulder pain. It is characterized by the inflammation of the rotator cuff tendons. Acute rotator cuff tendonitis may develop in athletes or workers that frequently lift their arm overhead, such as swimming. Chronic rotator cuff tendonitis may develop as a result of arthritis or repetitive wear-and-tear due to age. The symptoms of rotator cuff tendonitis usually to worsen over time. Symptoms that extend beyond the elbow usually indicate another problem.

Rotator cuff tendinopathy, which is pain and weakness in the rotator cuff tendons, may develop from repetitive overhead activities.

Rotator cuff tear

Rotator cuff tears are caused by overuse or acute injury. It can be a partial or complete tear. These injuries can cause intense and severe pain, limiting day-to-day activities. You may also experience shoulder weakness and popping sensations as you move your arm.

The rotator cuff tendon can tear from a sudden injury, like falling on an outstretched arm. It can also result from repetitive motion or chronic degenerative change.

If you tore your rotator cuff, you might find it challenging to raise your arm above shoulder height.

Impingement (painful arch syndrome)

Shoulder impingement happens when the acromion (top of the shoulder blade) rubs (or “impinges”) the rotator cuff tendons and bursa when the arm is raised overhead. You will feel pain in the shoulder.

Postures that may cause impingement are:

  • Arm directly overhead
  • Arm working at or near shoulder height

Common symptoms of rotator cuff impingement include:

  • An arc of shoulder pain when the arm is overhead or at shoulder height
  • Pain when lying on the shoulder
  • Shoulder pain that can radiate from the top of the shoulder to the elbow
  • Dull lingering pain in the upper arm
  • Pain or weakness when lifting
  • Pain when lifting your arm, especially when putting it behind your back or head
  • Pain reaching for the seatbelt

If your hand is stiff, you might have a frozen shoulder instead.

Frozen shoulder (adhesive capsulitis)

A frozen shoulder (adhesive capsulitis) occurs when abnormal bands of tissues build up in the joint. This causes the shoulder joint to become stiff and unable to move freely.

Your shoulder might “freeze” gradually over time, possibly because you use the shoulder less due to pain, allowing the adhesions to build up. As a consequence, your shoulder joint doesn’t have sufficient space to rotate adequately. This makes it difficult to reach overhead or scratch your back.

People with a frozen shoulder may experience pain, stiffness, and a decrease in range of motion. When the pain is severe, you might not be able to do everyday tasks that involve shoulder movement.

Bicep tendonitis or tendinopathy

Bicep tendonitis is an inflammation of the biceps tendons. It occurs at the long head, where it connects the biceps muscle (at the front of the arm) to the shoulder and elbow.

The inflammation in the biceps tendon occurs as a result of repetitive overhead motion. Sports with repeated movement in the shoulder can cause bicep tendonitis – this includes swimming, tennis, and baseball.

In the early stages of bicep tendonitis, the biceps tendon becomes red and swollen. As the condition develops the tendon sheath (covering) as well as the tendon itself may thicken. Occasionally, the damage to the biceps tendon may result in a tear or deformity in the upper arm (a “Popeye” bulge).

Common symptoms are:

  • Pain in the front of the shoulder that worsens when reaching overhead or lifting heavy objects
  • The pain may occasionally radiate down the elbow
  • Muscle weakness or snapping with shoulder movements

Bicep tendonitis usually occurs in conjunction with other shoulder problems. In most cases, you will also have a tear in the rotator cuff tendon. Other issues that may accompany bicep tendinitis include arthritis, glenoid labrum tear, shoulder instability, and impingement.

Bursitis

Subacromial bursitis occurs when there is inflammation of the bursa between the rotator cuff and acromion. It most commonly occurs as a result of repetitive movement or overuse.

When the shoulder bursa gets irritated, it becomes inflamed and enlarged, thereby narrowing the space for muscles and tendons to move freely. This can cause pain in the tip of the shoulder and a loss of movement. You might not be able to raise your arm above your head.

Common symptoms of subacromial bursitis include:

  • Pain on the tip of the shoulder
  • Pain when the arm is raised
  • Pain that radiates down the arms towards the elbow or wrist
  • Pain that worsens when you move the arm overhead or when lying on it
  • Painful arc movement when you move the arm up and outwards
  • Tenderness
  • Limited range of motion
  • Swelling and redness

Shoulder bursitis is often accompanied by rotator cuff tendinitis.

Instability

Shoulder instability happens when the head of the humerus (upper arm bone) is forced out of the shoulder socket. It occurs as a result of overuse or a traumatic injury.

Once the tendons, ligaments, and muscles around the shoulder become torn or loose, dislocations can occur recurrently. Recurring dislocations may be partial (subluxation) or complete. It causes pain and unsteadiness when you raise your arm or move it away from your body. Over time, repeated episodes of dislocations can lead to osteoarthritis.

Osteoarthritis

Osteoarthritis results from wear-and-tear. In this form of arthritis, the cartilage between the bone wears away, causing the bones to rub together. This can cause pain, swelling, and stiffness. Symptoms generally worsen over time.

Osteoarthritis may affect your shoulder joints if it has been put under excessive stress, or if you’ve had a previous injury. For some people, a prior shoulder injury from sports or vigorous physical activity may kick off the degenerative process that years later culminates in osteoarthritis. But it usually has no specific cause – it’s merely wear-and-tear over time.

Osteoarthritis commonly occurs in either the acromioclavicular joint or the glenohumeral joint. You will feel a deep ache in the back of the shoulder. Eventually, as the disease progresses, you will feel stiffness in the shoulder, making it difficult to reach overhead or behind your back.

Polymyalgia rheumatica

Polymyalgia rheumatica is an inflammatory condition that triggers pain and stiffness in the muscles of the shoulders and pelvis. These symptoms are usually felt on both sides of the body. Other common symptoms include low-grade fever, malaise, and a loss of appetite. The symptoms tend to be worse in the morning and gradually improve throughout the day.

Some people with polymyalgia rheumatica are also diagnosed with a related disorder called temporal arteritis.

Rheumatoid arthritis

Rheumatoid arthritis causes your immune system to attack the synovium (lining of the joints). It is more common in the hands and feet, but can also affect the shoulders. You may experience pain, tenderness, and stiffness.

Bone spur

A bone spur, or osteophyte, is a hard bony growth form at the point where two bones meet, causing the bones to rub against each other.

In the shoulder, a bone spur may develop under the acromion, which can, in turn, pinch the rotator cuff. As a result, the rotator cuff tendons can become frayed and irritated. This can cause pain, muscle spasms, and loss of mobility. It may also lead to rotator cuff tendonitis.

The formation of a bone spur is common with aging or repetitive use of the shoulder. People with sports or jobs that require repetitive overhead movement are susceptible to this condition.

Shoulder Fracture

Fractures in the shoulder bones may result from a traumatic blow to the shoulder or a fall onto an outstretched hand. It tends to cause severe pain, bruising, tenderness, and swelling around the shoulder. The bone may also protrude out of position.

Shoulder dislocation

The shoulder becomes dislocated when the ball of the upper arm bone pops out of its socket. It may recur if the surrounding structures of the shoulder wear off.

Symptoms include pain, swelling, weakness, numbness, and bruising in your shoulder. The arm may look out of place.

Shoulder separation

A shoulder separation occurs when the ligaments in the acromioclavicular region between the collarbone and shoulder blade tear. It may result from falls or traumatic blows.

Symptoms include pain, swelling, and tenderness in the front shoulder, as well as a bump at the point of separation. If your collarbone is pushed out of place, you’ll have a bump on top of your shoulder.

Referred neck pain

Your shoulder pain may sometimes originate from an injury in another part of your body, especially your neck (referred neck pain).

Pain is generally felt in the shoulder blade or upper outer arm. This type of pain usually doesn’t worsen when you move your shoulder. You may also experience a pins-and-needles or tingling sensation in your hand or arm.

Lung conditions

Certain lung conditions, such as lung cancer and mesothelioma, may also cause referred pain in the shoulder blades. Other possible causes include pneumothorax (a collapsed lung) and pulmonary emboli (a blood clot that travels from the legs to the lungs).

Heart conditions

A heart attack may cause pain in the shoulder blades, especially among women. Other signs, such as shortness of breath and chest pain, may also be present.

Pain in the left shoulder blade may also indicate conditions such as aortic dissection (a tear in the aorta) or pericarditis (inflammation of the heart lining).

Seek immediate treatment if you experience these symptoms.

Abdominal conditions

Some conditions occur in the abdomen that may cause shoulder pain, including:

  • Surgery
  • Nerve pain
  • Peptic ulcer disease
  • Pancreatitis
  • Liver disease

 

When to see a doctor

If you’ve had a severe injury or get sudden, continuous pain, and the condition doesn’t improve, you should see your doctor for further evaluation.

See your doctor if you experience any of the following:

  • Intense pain that is unusual or recurring
  • Stiffness that prevent you from lifting or rotating your arm
  • Weakness in the shoulder, arm, or hand
  • Separated or dislocated shoulder, or if it feels like your shoulder could slide out

Call emergency care if you have sudden shoulder pain that is accompanied by breathing difficulty, chest tightness, excessive sweating, dizziness, and pain in the neck or jaw – these are potential signs of a heart attack.

 

Diagnosis

A thorough clinical evaluation may help to pinpoint the cause of your shoulder pain. Briefly, your doctor will carry out a medical history and physical examination. They may also order imaging tests.

Medical history

Your doctor would attempt to understand your medical history – how and when the pain started, whether it is recurring, and how it is treated.

Physical examination

An examination of the shoulder can reveal any physical abnormalities, swelling, or tenderness. Your doctor may also check for your range of motion and joint stability.

Imaging tests

Your doctor may order imaging tests of your shoulder to identify the cause of your pain:

  • X-ray images will reveal any injuries to the shoulder bones or joints. However, they won’t show injuries to soft tissues like muscles, such as in rotator cuff injuries.
  • Magnetic resonance imaging (MRI) and ultrasound create detailed images of the soft tissues and reveal any signs of fluid and inflammation.
  • Computed tomography (CT) scan combines x-rays with computing to generate a detail view of the bones in the shoulder area.
  • Nerve conduction studies, such as an electromyogram (EMG) can be used to evaluate nerve function. It can reveal whether you have a pinched or irritated nerve by measuring the electrical conduction in the affected area.
  • Arthrogram reveals the joint and its surrounding muscles and tendons.
  • Arthroscopy is a surgical procedure whereby a fiber-optic camera is used to detect any soft tissue injuries that are not apparent with other diagnostic tests.

 

Treatment

The goal of treatment is to reduce pain and restore function in the shoulder. Treatment will depend on the severity and cause of the shoulder pain, as well as your activity level and overall health.

Physical therapy

Stretch and strengthen your shoulders to improve range of motion and ease the pain. You may benefit from exercises that:

  • Strengthen weakened muscles change their coordination and improve function.
  • Ease or prevent stiffness
  • Increase the range of joint motion

The physiotherapist may also perform manual treatments to the joints and soft tissues – such as massage and manual manipulation.

It could take weeks to months to see improvement.

Occupational therapy

If your shoulder pain is making it difficult to carry out daily activities, such as driving or dressing, it may help to consult an occupational therapist.

An occupational therapist can show you how to change your movements to help prevent pain from recurring. They can also advise on the types of equipment or adaptations that could reduce the strain on your shoulder.

Steroid injections

Steroid injections can ease inflammation around the shoulder joint. Your symptoms should improve relatively quickly. The effects may be temporary, lasting only for a few weeks.

While the injection may be repeated, having more than two or three sessions isn’t usually recommended because it might cause more damage to your shoulder tendon in the long term. If the problem keeps recurring, you might need to find another solution.

 

Managing your symptoms

You can usually manage mild symptoms without having to see a doctor. Here are several ways you can relieve shoulder pain.

Painkillers

Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, can relieve pain and inflammation. Likewise, aspirin and acetaminophen can also help ease the pain. If your pain is severe, prescription painkillers may be necessary.

You can also try topical pain relief gels and creams, which don’t have the same side effects as oral pain medications.

Heat or cold therapy

A cold compress, or ice pack, may be helpful if your shoulder is painful, swollen, or tender. Do not apply ice directly to the skin.

Heat compress, or heating pad, can help to relax tense muscles and ease stiffness. It may help with muscle pain and arthritis.

Ideally, alternate between hot and cold treatments. Use for 15 minutes at a time at 4 to 6-hour intervals.

Compression

Wrap a regular ACE bandage or a cold compression bandage around the shoulder to help reduce swelling and pain.

Wrap it snugly but not too tight – you don’t want to restrict blood flow. If your shoulder begins to feel numb or tingly, or turn blue, loosen the compression bandage.

Muscle relaxants

Muscle relaxants may help ease muscle tension or spasms around the joint. Common prescription muscle relaxants include cyclobenzaprine, tizanidine, and baclofen.

Improve posture

Poor posture, such as slouching at your workstation, can worsen your shoulder pain.

Try these tips:

  • While seated, avoid leaning forward and resting on your arms.
  • Relax your shoulders and allow your arms to hang by your sides.
  • Sit in an upright position.
  • Change your position regularly.
  • Support your lower back with a cushion or use an ergonomic chair with adequate lumbar support
  • Hold your shoulder blades down and back

If your shoulder hurts when you lie down, try:

  • Lying on your good side with a pillow under your neck
  • Support your arm with a pillow

Activity Modification

Stay active, even if you don’t feel you can move your shoulder much. If you keep a delicate balance between rest and activity, it should prevent your shoulder from stiffening.

Try avoiding movements that hurt. Do not raise your arm above your shoulder or hold it away from your body so that you won’t aggravate the pain.

You may ice your shoulders before and after activity.

 

Prevention

The following measures can help prevent shoulder pain:

  • Simple shoulder exercises that stretch and strengthen the shoulder muscles. Use ice for 15 minutes before exercising.
  • Practice good posture. Try to sit and stand tall. Avoid slouching.
  • Don’t lift heavy items. Heavy lifting can lead to shoulder injuries, which could trigger in the shoulder blades. If you do have to lift something, bend your knees, and try not to put too much pressure on your back.
  • Don’t sit for too long. Get up and frequently stretch when you’re working at a computer or desk. This can help keep muscles loose. You can also try a standing desk.

 

The Bottom Line

Should pain is a common complaint. The unique anatomy and flexibility of the shoulder make it susceptible to injury. Common triggers for shoulder injury include accidents, repetitive movements, manual labor, extreme sports, and aging.

It is essential to know the cause so that an effective treatment plan can be curated to address the underlying issue. For simple cases, you may recover fully with home remedies and gentle exercises.