Tendonitis is a condition where a tendon—the thick, fibrous tissue that connects muscles to bones—becomes inflamed or irritated. This inflammation usually happens because of repetitive motion, overuse, injury, or strain. Tendons are designed to handle stress, but when they are pushed beyond their limits repeatedly or suddenly, tiny tears can develop, leading to swelling, pain, and difficulty moving the affected area. For example, elbow tendonitis occurs when the tendons around the elbow get inflamed, often due to repetitive arm movements like those in tennis or golf. Symptoms typically include pain or tenderness near the joint, swelling, stiffness (especially in the morning), and weakness in grip or movement. The pain usually worsens with activity and improves with rest. Tendonitis can affect various parts of the body, such as the elbow, knee (quadriceps tendonitis), ankle (peroneal tendonitis), shoulder (bicep tendonitis), and Achilles tendon, among others.
Arthritis, on the other hand, is a broader term that refers to inflammation of the joints themselves. It is not limited to tendons but involves the joint structures, including cartilage, synovial membranes, and sometimes the bones. Arthritis can be caused by wear and tear (osteoarthritis), autoimmune diseases (rheumatoid arthritis), infections, or other factors. The main symptoms of arthritis include joint pain, swelling, stiffness, and reduced range of motion. Unlike tendonitis, which primarily affects tendons, arthritis affects the joint as a whole and can lead to joint damage over time.
The key differences between tendonitis and arthritis lie in what tissues are affected and the underlying causes:
– **Tissue affected:** Tendonitis involves inflammation of tendons, while arthritis involves inflammation of the joint structures, including cartilage and synovial lining.
– **Cause:** Tendonitis is usually caused by repetitive strain, overuse, or injury to tendons. Arthritis can be caused by degenerative changes, autoimmune reactions, infections, or metabolic issues.
– **Symptoms:** Tendonitis symptoms are localized to the tendon area with pain that worsens during movement and improves with rest. Arthritis symptoms often include joint pain, swelling, stiffness (especially after periods of inactivity), and sometimes systemic symptoms like fatigue in autoimmune types.
– **Location of pain:** Tendonitis pain is often just outside or around the joint where the tendon attaches, while arthritis pain is centered in the joint itself.
– **Progression:** Tendonitis can often be resolved with rest, physical therapy, and anti-inflammatory treatments if caught early. Arthritis is typically a chronic condition that may progressively worsen and require long-term management.
For example, in the case of elbow pain, tendonitis would cause tenderness and pain on the inner or outer side of the elbow where the tendon is inflamed, often linked to repetitive arm use. Arthritis in the elbow would cause pain more deeply within the joint, stiffness, and swelling that might not improve simply with rest.
Similarly, quadriceps tendonitis causes pain just above the kneecap where the tendon connects the thigh muscle to the bone, especially during activities like running or squatting. Knee arthritis causes pain inside the knee joint itself, often accompanied by swelling and stiffness that can limit walking or climbing stairs.
In terms of diagnosis, doctors distinguish between tendonitis and arthritis through patient history, physical examination, and sometimes imaging tests like X-rays or MRI scans. Tendonitis is identified by tenderness along the tendon, pain with specific movements, and sometimes swelling. Arthritis is diagnosed by joint swelling, decreased range of motion, joint deformities, and imaging showing cartilage loss or bone changes.
Treatment approaches also differ. Tendonitis treatment focuses on reducing inflammation and allowing the tendon to heal through rest, ice, anti-inflammatory medications, physical therapy, and sometimes injections or surgery if severe. Arthritis treatment aims to manage pai