Key Takeaways
- Tendonitis is inflammation or irritation of a tendon — the fibrous tissue connecting muscle to bone — most often caused by overuse, injury, or repetitive strain, and it commonly affects the Achilles tendon in the heel, the patellar tendon in the knee, and the rotator cuff tendons in the shoulder.
- Tendonitis and tendinosis are different: tendonitis is inflammation from acute injury or overuse, while tendinosis is a chronic, degenerative breakdown of tendon fibers without inflammation that often requires longer rehab focused on stimulating healing.
- Common signs of tendonitis include localized pain near the tendon, swelling and tenderness, stiffness with reduced range of motion, and pain that worsens with activity or exercise.
- Risk factors for tendonitis include repetitive motions or overuse, sudden increases in activity intensity, poor biomechanics or technique, age-related tendon degeneration, and pre-existing conditions such as diabetes or arthritis.
- Rehab approaches include stretching and strengthening exercises, manual therapy, and eccentric training, alongside measures like ice therapy, activity modification, and — under physician guidance — options such as ultrasound, laser therapy, or platelet-rich plasma (PRP) injections.
Frequently Asked Questions
What is tendonitis?
Tendonitis is inflammation or irritation of a tendon, the fibrous tissue that connects muscle to bone. It leads to pain, swelling, stiffness, and impaired movement in the affected area.
What's the difference between tendonitis and tendinosis?
Tendonitis is inflammation of the tendon caused by acute injury or overuse, while tendinosis is a chronic, degenerative condition where tendon fibers break down without inflammation. Tendinosis often requires longer rehab focused on stimulating tendon healing rather than just reducing inflammation.
What causes tendonitis?
Tendonitis can be caused by repetitive motions or overuse in sports and work, a sudden increase in activity intensity or duration, poor biomechanics or improper technique, age-related tendon degeneration, and pre-existing conditions like diabetes or arthritis.
What are the signs and symptoms of tendonitis?
Common symptoms include localized pain near the tendon, swelling and tenderness, stiffness with reduced range of motion, and pain that worsens with activity or exercise.
How is tendonitis treated?
Treatment may include stretching and strengthening exercises, manual therapy, and eccentric training to strengthen the tendon under load. Additional approaches include ice therapy, NSAIDs as recommended by a healthcare provider, activity modification, ultrasound or laser therapy, and platelet-rich plasma (PRP) injections in some cases under physician guidance.


















































