Shoulder Pain

 Pain in the shoulder area is a common complaint and can arise for a number of reasons.

This article reviews the possible causes of shoulder pain and describes how to go about finding a diagnosis and a treatment plan. Please don't attempt to use what's written here as an alternative to seeking advice from a qualified doctor or therapist. The information on this page is provided for educational purposes only

 Not all shoulder pain originates in the shoulder and it's important to keep this in mind when trying to figure out what might be wrong - or what the cause of the pain might be.

Referred pain describes the well recognised situation when a problem in one area of the body "tricks the brain" into thinking the pain is arising somewhere else.

Referred pain to the shoulder can arise from:

• the neck - a problem with the joints or discs or nerves of the cervical spine can send referred pain into the shoulder region and also down the arm towards the hand. This kind of referred neck pain is often accompanied by tingling or pins and needles in the hand
• the heart - pain around the left shoulder can sometimes arise as a result of heart problems. This is not typical but it can sometimes be found in people suffering from angina. The clue often lies in the fact that the shoulder or arm pain is provoked by exercise and relieved again by rest.
• the abdominal organs - gallstones, stomach ulcers or other conditions that upset the liver or the diaphragm muscle can send pain to the shoulder tip (most commonly the right shoulder tip but it can be the left too at times)
• other joints nearby - the small joint between the collar bone and the shoulder blade (called the acromioclavicular or AC joint) can sometimes send pain downwards to the shoulder area

The phenomenon of referred pain is one reason why it's always important to seek a proper diagnosis of your shoulder pain condition - don't attempt to make the diagnosis yourself or you could be putting your health at significant risk.

OK - leaving referred pain aside then, what are the common reasons for true shoulder pain?

These are the shoulder pain problems seen most frequently:

1. Bursitis of the shoulder   The bursa is a bag of fluid that surrounds the muscles and the upper surface of the joint. It's function is to allow the muscles to move without friction. If it becomes inflamed due to injury or due to overuse then the condition is called "Bursitis" - anything "-itis" means inflamed. So "Burs-itis" = inflamed bursa. There are several bursae around the shoulder but the most common one to be inflamed is called the subdeltoid or subacromial bursa. Bursitis can occur on its own or it can be associated with injury to the rotator cuff muscles or with a tear in those muscles.   
2. Rotator Cuff Injury   The rotator cuff is a group of four muscles that surround the shoulder. They help to keep it stable as it moves and are also responsible for triggering the commonest patterns of shoulder movement. Injury to the rotator cuff is common in the younger age groups as a result of sport related trauma but is also found quite frequently in older age ranges due to degenerate changes in the muscles and tendons with associated inflammation and tearing.   
3. Frozen Shoulder   Frozen shoulder is also known as adhesive capsulitis. It can start after injury or sometimes appear out of the blue with no obvious or apparent trigger factors. The capsule is a bag of gristle that surrounds the shoulder joint and helps to stabilise it. Capsulitis is inflammation in the capsule and the inflamed capsule sticks to the underlying bone and joint. This stickiness results in both pain and a "freezing up" of the joints ability to move - hence the name "frozen shoulder." Frozen shoulder progresses through three phases - lasting up to 18 months in total. There's a freezing up stage, a frozen stage and a thawing out stage and the pattern of pain and disability varies in each.   
4. Shoulder arthritis   True joint damage or arthritis is not common at the shoulder but it can be seen with three or four different conditions. Rheumatoid arthritis can affect the shoulder but it only usually does this when other joints are also affected and the diagnosis is often very clear cut. Osteoarthritis rarely affects the shoulder - except in cases where there has been injury some time previously Gout arthritis can sometimes show itself in the shoulder without any signs elsewhere in the body - a blood test is usually needed to make the diagnosis properly Infective or "septic" arthritis is very rare but should always be considered when faced with signs of joint inflammation in the shoulder. Early treatment of septic arthritis is vital if long term damage is to be avoided.   
5. Shoulder Injury   Common injuries to the shoulder include: Shoulder dislocation - usually downwards or to the front of the joint Shoulder muscle or tendon tear - usually to the rotator cuff but also sometimes to the biceps or triceps muscles Tears to the glenoid labrum - sometimes called a SLAP tear Shoulder separation - a condition seen after dislocation or subluxation and usually associated with a long term unstable joint

 Most cases of shoulder pain are diagnosed clinically by a doctor or a therapist who is experienced in assessing shoulder joint problems.

Carefully listening to the story the patient gives and then carefully examining the area is enough in most cases to arrive at a diagnosis and then to make a plan for treatment.

Sometimes further investigation is needed:

Common shoulder pain investigations include:

• Blood tests - done if the doctor suspects that there could be another condition triggering the shoulder pain problem. Blood tests can show evidence of infection, of gout or of generalised inflammation in the whole body such as could be seen with rheumatoid arthritis or other similar diseases
• X-ray - most useful for looking at the bones themselves. X-rays can help diagnose shoulder arthritis, neck problems and might sometimes show evidence of calcium depositis in the rotator cuff tendons.
• Ultrasound scan - this is similar to the scan done for women during pregnancy. Sound waves are beamed into the shoulders and the reflections of these waves can be analysed by a computer and used to build up images of the internal components of the shoulder. Ultrasound scanning is helpful when a rotator cuff tear is suspected
• MRI Scanning - often referred to as the gold standard of investigation for shoulder complaints. MRI allows a close look at all parts of the shoulder including the joint, the muscles and the tendons. Sometimes the images can be made even clearer by injecting die or contrast into the joint - this latter test is called an MRI arthrogram.

 This page has been written by shoulder expert Doctor Gordon Cameron. You can read more shoulder related material and download a copy of a comprehensive shoulder pain ebook on Doctor Cameron's painful shoulder website.