Shoulder arthritis can be one of three types of arthritis in the glenohumeral joint of the shoulder. The glenohumeral joint is a ball and socket joint, which relies on cartilage to move smoothly and to operate normally.

The main symptom of shoulder arthritis is pain; this is due to the grinding of the bones against each other because of the lack of cartilage. Pain usually occurs in the front of the shoulder and is worse with motion. People with shoulder arthritis will also experience moderate to severe weakness, stiffness developing over many years, and the inability to sleep on the affected shoulder.

In general, pigmented villonodular synovitis often manifests initially as sudden onset, unexplained joint swelling and pain; the joint swelling is disproportionate to the amount of pain the patient feels at first. Decreased motion and increased pain occur as the disorder progresses as well as locking of the joint. The localized form often manifests initially as a painless, slow-growing mass and progresses to the other common symptoms of PVNS. The swelling often feels warm to the touch. Diffuse PVNS symptoms are often confused with those of Rheumatoid arthritis. While pigmented villonodular synovitis can occur in both pediatric and geriatric patients, it is more common with ages 20–50.

Pain is often aggravated by elevation of the arm above shoulder level or by lying on the shoulder. Pain may awaken the patient from sleep. Other complaints may be stiffness, snapping, catching, or weakness of the shoulder.

For a person with arthritis mutilans in the hands, the fingers become shortened by arthritis, and the shortening may become severe enough that the hand looks paw-like, with the first deformity occurring at the interphalangeal and metacarpophalangeal joints. The excess skin from the shortening of the phalanx bones becomes folded transversely, as if retracted into one another like opera glasses, hence the description "la main en lorgnette". As the condition worsens, luxation, phalangeal and metacarpal bone absorption, and skeletal architecture loss in the fingers occurs.

Subacromial bursitis often presents with a constellation of symptoms called impingement syndrome. Pain along the front and side of the shoulder is the most common symptom and may cause weakness and stiffness. If the pain resolves and weakness persists other causes should be evaluated such as a tear of the rotator cuff or a neurological problem arising from the neck or entrapment of the suprascapular nerve. The onset of pain may be sudden or gradual and may or may not be related to trauma. Night time pain, especially sleeping on the affected shoulder, is often reported. Localized redness or swelling are less common and suggest an infected subacromial bursa. Individuals affected by subacromial bursitis commonly present with concomitant shoulder problems such as arthritis, rotator cuff tendinitis, rotator cuff tears, and cervical radiculopathy (pinched nerve in neck).

Impingement may be brought on by sports activities, such as overhead throwing sports and swimming, or overhead work such as painting, carpentry, or plumbing. Activities that involve repetitive overhead activity, or directly in front, may cause shoulder pain. Direct upward pressure on the shoulder, such as leaning on an elbow, may increase pain.

Bursitis commonly affects superficial bursae. These include the subacromial, prepatellar, retrocalcaneal, and pes anserinus bursae of the shoulder, knee, heel and shin, etc. (see below). Symptoms vary from localized warmth and erythema to joint pain and stiffness, to stinging pain that surrounds the joint around the inflamed bursa. In this condition, the pain usually is worse during and after activity, and then the bursa and the surrounding joint becomes stiff the next morning.

PVNS is locally aggressive and can spread to surrounding tissues, causing bone erosion and tissue damage. If not treated early, it can spread to areas outside the joint, and potentially cause permanent loss of range as well as intense pain. The disorder also has, on average, a 45% rate of recurrence.

Those with hypermobile joints are more likely to have fibromyalgia, mitral valve prolapse, and anxiety disorders such as panic disorder.

People with Joint Hypermobility Syndrome may develop other conditions caused by their unstable joints. These conditions include:

- Joint instability causing frequent sprains, tendinitis, or bursitis when doing activities that would not affect others

- Joint pain

- Early-onset osteoarthritis (as early as during teen years)

- Subluxations or dislocations, especially in the shoulder (severe limits to ability to push, pull, grasp, finger, reach, etc., is considered a disability by the US Social Security Administration)

- Knee pain

- Fatigue, even after short periods of exercise

- Back pain, prolapsed discs or spondylolisthesis

- Joints that make clicking noises (also a symptom of osteoarthritis)

- Susceptibility to whiplash

- Temporomandibular Joint Syndrome also known as TMJ

- Increased nerve compression disorders (such as carpal tunnel syndrome)

- The ability of finger locking

- Poor response to anaesthetic or pain medication

- "Growing pains" as described in children in late afternoon or night

Arthritis mutilans is a rare medical condition involving severe inflammation damaging the joints of the hands and feet, and resulting in deformation and problems with moving the affected areas; it can also affect the spine. As an uncommon arthropathy, arthritis mutilans was originally described as affecting the hands, feet, fingers, and/or toes, but can refer in general to severe derangement of any joint damaged by arthropathy. First described in modern medical literature by Marie and Leri in 1913, in the hands, arthritis mutilans is also known as opera glass hand ("la main en lorgnette" in French), or chronic absorptive arthritis. Sometimes there is foot involvement in which toes shorten and on which painful calluses develop in a condition known as opera glass foot, or "pied en lorgnette".

Calcific tendinitis is a form of tendinitis, a disorder characterized by deposits of hydroxyapatite (a crystalline calcium phosphate) in any tendon of the body, but most commonly in the tendons of the rotator cuff (shoulder), causing pain and inflammation. The condition is related to and may cause adhesive capsulitis ("frozen shoulder").

Shoulder problems including pain, are one of the more common reasons for physician visits for musculoskeletal symptoms. The shoulder is the most movable joint in the body. However, it is an unstable joint because of the range of motion allowed. This instability increases the likelihood of joint injury, often leading to a degenerative process in which tissues break down and no longer function well.

Shoulder pain may be localized or may be referred to areas around the shoulder or down the arm. Other regions within the body (such as gallbladder, liver, or heart disease, or disease of the cervical spine of the neck) also may generate pain that the brain may interpret as arising from the shoulder.

"Adhesive capsulitis" (also known as "frozen shoulder") is a painful and disabling disorder of unclear cause in which the shoulder capsule, the connective tissue surrounding the glenohumeral joint of the shoulder, becomes inflamed and stiff, greatly restricting motion and causing chronic pain. Pain is usually constant, worse at night, and with cold weather. Certain movements or bumps can provoke episodes of tremendous pain and cramping. The condition is thought to be caused by injury or trauma to the area and may have an autoimmune component.

Risk factors for frozen shoulder include tonic seizures, diabetes mellitus, stroke, accidents, lung disease, connective tissue diseases, thyroid disease, and heart disease. Treatment may be painful and taxing and consists of physical therapy, occupational therapy, medication, massage therapy, hydrodilatation or surgery. A physician may also perform manipulation under anesthesia, which breaks up the adhesions and scar tissue in the joint to help restore some range of motion. Alternative treatments exist such as the Trigenics OAT Procedure, ART, and the OTZ method. But these can vary in efficacy depending on the type and severity of the frozen shoulder. Pain and inflammation can be controlled with analgesics and NSAIDs.

People who suffer from adhesive capsulitis usually experience severe pain and sleep deprivation for prolonged periods due to pain that gets worse when lying still and restricted movement/positions. The condition can lead to depression, problems in the neck and back, and severe weight loss due to long-term lack of deep sleep. People who suffer from adhesive capsulitis may have extreme difficulty concentrating, working, or performing daily life activities for extended periods of time. The condition tends to be self-limiting and usually resolves over time without surgery. Most people regain about 90% of shoulder motion over time.

Bursitis is the inflammation of one or more bursae (small sacs) of synovial fluid in the body. They are lined with a synovial membrane that secretes a lubricating synovial fluid. There are more than 150 bursae in the human body. The bursae rest at the points where internal functionaries, such as muscles and tendons, slide across bone. Healthy bursae create a smooth, almost frictionless functional gliding surface making normal movement painless. When bursitis occurs, however, movement relying on the inflamed bursa becomes difficult and painful. Moreover, movement of tendons and muscles over the inflamed bursa aggravates its inflammation, perpetuating the problem. Muscle can also be stiffened.

Subacromial bursitis is a condition caused by inflammation of the bursa that separates the superior surface of the supraspinatus tendon (one of the four tendons of the rotator cuff) from the overlying coraco-acromial ligament, acromion, coracoid (the acromial arch) and from the deep surface of the deltoid muscle. The subacromial bursa helps the motion of the supraspinatus tendon of the rotator cuff in activities such as overhead work.

Musculoskeletal complaints are one of the most common reasons for primary care office visits, and rotator cuff disorders are the most common source of shoulder pain.

Primary inflammation of the subacromial bursa is relatively rare and may arise from autoimmune inflammatory conditions such as rheumatoid arthritis; crystal deposition disorders such as gout or pseudogout; calcific loose bodies, and infection. More commonly, subacromial bursitis arises as a result of complex factors, thought to cause shoulder impingement symptoms. These factors are broadly classified as intrinsic (intratendinous) or extrinsic (extratendinous). They are further divided into primary or secondary causes of impingement. Secondary causes are thought to be part of another process such as shoulder instability or nerve injury.

In 1983 Neer described three stages of impingement syndrome. He noted that "the symptoms and physical signs in all three stages of impingement are almost identical, including the 'impingement sign'..., arc of pain, crepitus, and varying weakness." The Neer classification did not distinguish between partial-thickness and full-thickness rotator cuff tears in stage III. This has led to some controversy about the ability of physical examination tests to accurately diagnose between bursitis, impingement, impingement with or without rotator cuff tear and impingement with partial versus complete tears.

In 2005, Park et al. published their findings which concluded that a combination of clinical tests were more useful than a single physical examination test. For the diagnosis of impingement disease, the best combination of tests were "any degree (of) a positive Hawkins-Kennedy test, a positive painful arc sign, and weakness in external rotation with the arm at the side," to diagnose a full thickness rotator cuff tear, the best combination of tests, when all three are positive, were the painful arc, the drop-arm sign, and weakness in external rotation.

Movement of the shoulder is severely restricted, with progressive loss of both active and passive range of motion. The condition is sometimes caused by injury, leading to lack of use due to pain, but also often arises spontaneously with no obvious preceding trigger factor (idiopathic frozen shoulder). Rheumatic disease progression and recent shoulder surgery can also cause a pattern of pain and limitation similar to frozen shoulder. Intermittent periods of use may cause inflammation.

In frozen shoulder, there is a lack of synovial fluid, which normally helps the shoulder joint, a ball and socket joint, move by lubricating the gap between the humerus (upper arm bone) and the socket in the shoulder blade. The shoulder capsule thickens, swells, and tightens due to bands of scar tissue (adhesions) that have formed inside the capsule. As a result, there is less room in the joint for the humerus, making movement of the shoulder stiff and painful. This restricted space between the capsule and ball of the humerus distinguishes adhesive capsulitis from a less complicated, painful, stiff shoulder.

Enthesopathies may take the form of spondyloarthropathies (joint diseases of the spine) such as ankylosing spondylitis, plantar fasciitis, and Achilles tendinitis. Enthesopathy can occur at the elbow, wrist, carpus, hip, knee, ankle, tarsus, or heel bone, among other regions. Further examples include:

- Adhesive capsulitis of shoulder

- Rotator cuff syndrome of shoulder and allied disorders

- Periarthritis of shoulder

- Scapulohumeral fibrositis

- Synovitis of hand or wrist

- Periarthritis of wrist

- Gluteal tendinitis

- Iliac crest spur

- Psoas tendinitis

- Trochanteric tendinitis

The most common symptoms in impingement syndrome are pain, weakness and a loss of movement at the affected shoulder. The pain is often worsened by shoulder overhead movement and may occur at night, especially if the patient is lying on the affected shoulder. The onset of the pain may be acute if it is due to an injury or may be insidious if it is due to a gradual process such as an osteoarthritic spur. The pain has been described as dull rather than sharp, and lingers for long periods of a time, making it hard to fall asleep at night. Other symptoms can include a grinding or popping sensation during movement of the shoulder.

The range of motion at the shoulder may be limited by pain. A painful arc of movement may be present during forward elevation of the arm from 60° to 120°. Passive movement at the shoulder will appear painful when a downwards force is applied at the acromion but the pain will ease once the downwards force is removed.

As the name implies, movement of the shoulder is severely restricted in people with a "frozen shoulder". This condition, which doctors call adhesive capsulitis, is frequently caused by injury that leads to lack of use due to pain. Rheumatic disease progression and recent shoulder surgery can also cause frozen shoulder. Intermittent periods of use may cause inflammation. Adhesions (abnormal bands of tissue) grow between the joint surfaces, restricting motion. There is also a lack of synovial fluid, which normally lubricates the gap between the arm bone and socket to help the shoulder joint move. It is this restricted space between the capsule and ball of the humerus that distinguishes adhesive capsulitis from a less complicated painful, stiff shoulder. People with diabetes, stroke, lung disease, rheumatoid arthritis, and heart disease, or who have been in an accident, are at a higher risk for frozen shoulder. The condition rarely appears in people under the age of 40.

Symptoms may occur immediately after trauma (acute) or develop over time (chronic).

Acute injury is less frequent than chronic disease, but may follow bouts of forcefully raising the arm against resistance, as occurs in weightlifting, for example. In addition, falling forcefully on the shoulder can cause acute symptoms. These traumatic tears predominantly affect the supraspinatus tendon or the rotator interval and symptoms include severe pain that radiates through the arm, and limited range of motion, specifically during abduction of the shoulder.

Chronic tears occur among individuals who constantly participate in overhead activities, such as pitching or swimming, but can also develop from shoulder tendinitis or rotator cuff disease. Symptoms arising from chronic tears include sporadic worsening of pain, debilitation, and atrophy of the muscles, noticeable pain during rest, crackling sensations (crepitus) when moving the shoulder, and inability to move or lift the arm sufficiently, especially during abduction and flexion motions.

Pain in the anterolateral aspect of the shoulder is not specific to the shoulder, and may arise from, and be referred from, the neck, heart or gut.

Patient history will often include pain or ache over the front and outer aspect of the shoulder, pain aggravated by leaning on the elbow and pushing upwards on the shoulder (such as leaning on the armrest of a reclining chair), intolerance of overhead activity, pain at night when lying directly on the affected shoulder, pain when reaching forward (e.g. unable to lift a gallon of milk from the refrigerator). Weakness may be reported, but is often masked by pain and is usually found only through examination. With longer-standing pain, the shoulder is favored and gradually loss of motion and weakness may develop, which, due to pain and guarding, are often unrecognized by the patient and only brought to attention during examination.

Primary shoulder problems may cause pain over the deltoid muscle intensified by abduction against resistance - the impingement sign. This signifies pain arising from the rotator cuff, but cannot distinguish between inflammation, strain, or tear. Patients may report that they are unable to reach upwards to brush their hair or to lift a food can from an overhead shelf.

In medicine, an enthesopathy refers to a disorder involving the attachment of a tendon or ligament to a bone. This site of attachment is known as the entheses.

If the condition is known to be inflammatory, it can more precisely be called an enthesitis.

The signs and symptoms of ankylosing spondylitis often appear gradually, with peak onset being between 20 and 30 years of age. Initial symptoms are usually a chronic dull pain in the lower back or gluteal region combined with stiffness of the lower back. Individuals often experience pain and stiffness that awakens them in the early morning hours.

As the disease progresses, loss of spinal mobility and chest expansion, with a limitation of anterior flexion, lateral flexion, and extension of the lumbar spine, are seen. Systemic features are common, with weight loss, fever, or fatigue often present. Pain is often severe at rest but may improve with physical activity, but inflammation and pain to varying degrees may recur regardless of rest and movement.

AS can occur in any part of the spine or the entire spine, often with pain referred to one or the other buttock or the back of the thigh from the sacroiliac joint.

Arthritis in the hips and shoulders may also occur. When the condition presents before the age of 18, it is more likely to cause pain and swelling of large lower limb joints, such as the knees. In prepubescent cases, pain and swelling may also manifest in the ankles and feet where heel pain and enthesopathy commonly develop. Less commonly ectasia of the sacral nerve root sheaths may occur.

About 40% of people with AS will also experience inflammation of the anterior chamber of the eye, causing eye pain, redness, floaters and sensitivity to light. This is thought to be due to the association that both AS and uveitis have with the inheritance of the HLA-B27 antigen.

Inflammation of the prostate occurs with increased frequency in men.

Cardiovascular involvement may include inflammation of the aorta, aortic valve insufficiency or disturbances of the heart's electrical conduction system. Lung involvement is characterized by progressive fibrosis of the upper portion of the lung.

Finger injuries are usually diagnosed with x-ray and can get to be considerably painful. The majority of finger injuries can be dealt with conservative care and splints. However, if the bone presents an abnormal angularity or if it is displaced, one may need surgery and pins to hold the bones in place.

Shoulder impingement syndrome, also called subacromial impingement, painful arc syndrome, supraspinatus syndrome, swimmer's shoulder, and thrower's shoulder, is a clinical syndrome which occurs when the tendons of the rotator cuff muscles become irritated and inflamed as they pass through the subacromial space, the passage beneath the acromion. This can result in pain, weakness and loss of movement at the shoulder.