Shoulder pain is accompanied by discomfort and limitations in shoulder mobility, with varying degrees among individuals.

The causes of shoulder pain can range from fractures and bursitis to instability, arthritis, or simply overuse. Overworking or excessive pressure on the shoulder are common reasons for shoulder pain experienced by many individuals.

It's not uncommon for people to be uncertain about the source of their shoulder pain, as the symptoms of both arthritis and bursitis are often similar. However, it's important to note that these are distinct medical conditions with different causes. To determine the cause of your shoulder pain, it's helpful to understand the differences between shoulder arthritis and bursitis.

What is Shoulder Arthritis?

Shoulder arthritis is a condition that occurs when the cartilage within the shoulder joints is damaged. It affects the largest ball-and-socket joint in the shoulder, also known as the glenohumeral joint, which connects the glenoid and humerus bones.

Shoulder arthritis is characterized by the deterioration of cartilage in the shoulder, both on the surface and in the deeper layers. Additionally, there is a type of shoulder arthritis known as Acromioclavicular (AC) joint arthritis, which affects the second shoulder joint, commonly referred to as the AC joint.

Shoulder arthritis is prevalent in individuals who are over 50 years of age, but it can also occur in younger people due to shoulder injuries or rheumatoid arthritis.

Commonly Known Shoulder Arthritis Types

There are five common types of shoulder arthritis that can cause pain and discomfort in the shoulder. These include:

• ‍Rheumatoid Arthritis (RA) - an autoimmune disease that is a prevalent form of shoulder arthritis. As RA often affects both sides of the body, if one shoulder is impacted, it is likely that the other is too. RA causes the joint linings to enlarge, leading to stiffness and discomfort.‍
• Osteoarthritis (OA) - the most common type of arthritis, caused by the degradation of cartilage at the ends of bones where they form joints. This leads to stiffness, discomfort, and a lack of joint mobility as the ends of the bones rub against each other.‍
• Post-Traumatic Arthritis (PA) - a type of Osteoarthritis that can occur as a result of a fracture or dislocation of the shoulder. Post-Traumatic Arthritis often heals on its own, but if symptoms persist for longer than six months, it may progress to a chronic condition.‍
• ‍Rotator Cuff Tear Arthropathy - a condition that develops when the rotator cuff cannot heal or if the tear is too large. It can cause significant discomfort and weakness if left untreated, making it difficult to elevate the arm over the head.‍
• Avascular Necrosis - a disorder that occurs when the blood supply to a bone is cut off, leading to the death of bone cells. Over time, the bone slowly collapses, damaging the cartilage that covers it, resulting in shoulder arthritis.

These are different types of shoulder arthritis that develop due to various reasons.

Symptoms of Shoulder Arthritis

Shoulder arthritis has two main forms: glenohumeral arthritis and acromioclavicular arthritis. It is caused by the degeneration of the rotator cuffs, joint lining infection, or inflammation. Here are some common symptoms of both types of shoulder arthritis:

• Gradual increase in pain that worsens over months or years.
• Limitation in movements such as lifting arms or legs.
• Pain intensifies during inactivity, such as upon waking.
• Treatment may include maintaining a healthy weight and performing exercises to alleviate symptoms.

What is Shoulder Bursitis?

Shoulder bursitis is a condition that occurs when the bursa, a padding between tissue and bones in joints, becomes filled with excess fluid. In many cases, shoulder bursitis occurs concurrently with shoulder tendonitis. Both conditions can limit arm movement and cause discomfort.

Shoulder bursitis is a common condition that occurs when the bursa, a padding between tissues and bones in joints, becomes inflamed due to overuse or repeated shoulder movements. Although bursitis can occur in any joint, it is most commonly found in the shoulder.

Overhead movements can increase the friction between tissues and bones, causing the bursae to become irritated and inflamed due to repeated contact. This can result in an accumulation of fluid in the bursa sacs, leading to bursitis.

Commonly Known Shoulder Bursitis Types

The three commonly recognized types of shoulder bursitis are:

• Chronic: This is the most typical form of shoulder bursitis and can be caused by recurrent injuries or episodes of acute bursitis. You may experience symptom-free periods followed by flare-ups that last for many months. This persistent inflammation may eventually lead to arm and shoulder weakness.
• Infectious (Septic): Rarely, infectious (septic) shoulder bursitis is caused by bacterial infections such as staph infections. In this unusual case, the shoulder may feel hot to the touch and have a red or purple appearance. You may also feel ill and have a fever, and experience severe shoulder pain.
• Acute: This type of bursitis frequently results from an injury or accident and manifests suddenly. Pain is felt when touching or moving the shoulder.

Symptoms of Shoulder Bursitis

Shoulder bursitis is caused by repetitive or excessive movements of the shoulder, resulting in damage or inflammation to the bursa located between the acromion and rotator cuff. This painful condition can make everyday tasks, such as combing hair, challenging to perform. 

Some of the Symptoms of Shoulder Bursitis are

Here is a list of common symptoms of shoulder bursitis:

• Increased pain with movement
• Worsening pain with repetitive movements
• Pain and tenderness on the top and outside of the shoulder
• Pain that subsides after resting
• Pain when lying on the affected shoulder
• Limited overhead shoulder movement and sharp pain
• Temporary inflammation that decreases over time

The best treatment for shoulder bursitis is rest, which can help reduce pain and inflammation.

How Do Shoulder Arthritis and Shoulder Bursitis Differ?

Shoulder arthritis and bursitis can cause discomfort and pain in the shoulders of individuals affected by these conditions. It's important for patients to understand the differences between these two conditions.

• Although the symptoms of shoulder pain caused by arthritis and bursitis may be similar, the severity and affected areas can differ.
• Arthritis is caused by the wear and tear of cartilage in the muscles, leading to pain when the muscle hasn't moved for an extended period of time. On the other hand, bursitis is caused by inflammation of the bursa.
• Due to the differences in symptoms, both conditions also require different treatments.
• Understanding these differences can help in determining the cause of shoulder pain, whether it be arthritis or bursitis.

Final Thought

Although the cause of shoulder pain in shoulder arthritis and bursitis conditions differ, both result in discomfort and pain that can affect daily activities. It is important to seek medical advice and undergo treatment to alleviate the symptoms and reduce pain in the shoulders.