What Is Tendinosis?

Tendinosis is an accumulation over time of small-scale injuries that don't heal properly; it is a chronic injury of failed healing in tendons. Although you can't see the tendinosis injury on the outside of your body, researchers can see the injury on the cellular scale by viewing slides of tendons under the microscope. Tendinosis can occur in many different areas, such as the wrist, forearm, elbow, shoulder, knee, and heel.


Tendons are rope-like structures that attach muscles to bones. Ligaments are similar structures that attach bones to other bones. When muscles and bones move, they exert stresses on the tendons and ligaments that are attached to them.

When your muscles move in new ways or do more work than they can handle, your muscles and tendons can sustain some damage on a cellular scale. If the increase in demand is made gradually, muscle and tendon tissues will usually heal, build in strength, and adapt to new loads. Athletes use these principles to build muscle and tendon strength with good training programs.

You can, however, do some activity that injures a tendon on a microscopic scale and then do more injury before the tendon heals. If you continue the injurious activity, you will gradually accumulate these micro-injuries. When enough injury accumulates, you'll feel pain. This kind of injury that comes on slowly with time and persists is a chronic injury. (Acute tendon injuries, on the other hand, are sudden tears that cause immediate pain and swelling.) Tendon injuries often require patience and careful rehabilitation with physical therapy because tendons heal more slowly than muscles.

Tendinosis vs Tendinitis vs Tendinopathy

The suffix "itis" means inflammation; the term tendinitis should be reserved for tendon injuries that involve acute injuries accompanied by inflammation. The suffix "osis" implies a pathology of chronic degeneration without inflammation, so doctors prefer the term tendinosis for chronic tendon injuries of failed healing. Tendinosis is an accumulation over time of microscopic tendon injuries that don't heal properly. Although inflammation can be involved in the initial stages of the injury, it is the inability of the tendon to heal that perpetuates the pain and disability. Tendinopathy is a term that has no implication about the pathology of the injury, so it is more general and is being used more frequently today. As mentioned on the The Injury page, there is currently some debate about the role of inflammation on the cellular level in tendinosis/tendinopathy.

Who Is At Risk?

keyboardTendinosis can result from long hours of activities such as playing sports, using computers, playing musical instruments, or doing manual labor. It can result from activities performed as part of your profession or recreation. Some occupations that have increased risk for chronic tendon injuries include assembly line workers, mail sorters, computer programmers, writers, court recorders, data entry processors, sign language interpreters, cashiers, professional athletes, and musicians.

Another risk factor for tendon problems is the use of certain drugs; four classes of drugs have been associated with tendinopathy: quinolones, long-term glucocorticoids, statins, and aromatase inhibitors. The most press has probably gone to antibiotics in the fluoroquinolone family, such as Cipro. After taking these drugs some people can have serious tendon injuries. Not all patients are aware of this risk and given the chance to decide whether to take an alternative antibiotic. For help or more information you can visit this website: SaferPills.org, The Quinolone Vigilance Foundation, and there is a case study with quite a bit of information here. I receive so many emails from people about fluoroquinolones that I thought I should mention the issue even though it is a different topic than the overuse kind of tendinosis injuries addressed by this website. Some studies have also been done on statins.

Minimizing Your Risk

You can minimize your risk for tendinosis by using equipment that has good ergonomic design and that is sized correctly for your body, by using good technique for your activity (whether it is sports, music, typing etc.), by taking plenty of breaks, by minimizing long overtime hours (easier said than done!), and by avoiding fluoroquinolone drugs (see the information in the Who Is At Risk section above for more about fluoroquinolones). You can also listen to your body's pain signals. Warning signs of tendinosis include burning, stinging, aching, tenderness to the touch, and stiffness.

Tendinosis usually sneaks up on you. At first the pain only comes after a long or hard session of the activity that aggravates it. Later, the pain comes at lower levels of the activity and lasts longer. Finally, the pain becomes a part of your daily life and even normal activities can make it worse. Try to catch the injury as early as you can.

What Should I Do If I Have Tendinosis?

You should see a doctor for diagnosis and treatment. Sports medicine doctors and physiatrists are often excellent choices for tendinosis care, and they will likely refer you to a physical therapist. You can also use this site to learn more about your injury and treatments for it.

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"Physicians must acknowledge that the cause is most often due to tendinosis, rather than tendinitis, and treat the problem using a fundamentally different paradigm." From Overuse Tendinosis, Not Tendinitis

A review in The Lancet published online in October 2010 found that corticosteroid injections only provided short-lived benefit with potential for longer-term harm.

”Tendinopathy is essentially the result of an imbalance between collagen type-1 and type-3 and we have discovered the molecular cause. This breakthrough has allowed us to find a way to alter the levels of collagen type-3 in tendons, with the ultimate aim to get patients with tendon injuries better quicker." Exciting research into a potential new treatment for tendinosis/tendinopathy, explained by Neal Millar, an academic consultant orthopaedic surgeon and clinical senior research fellow at the University of Glasgow, quoted in Scientific breakthrough unlocks potential novel tendon therapy.

“This study showed that significant improvement in healing outcomes could be achieved by the use of BMC (bone marrow concentrate) containing MSC (mesenchymal stem cells) as an adjunct therapy in standard of care rotator cuff repair. Furthermore, our study showed a substantial improvement in the level of tendon integrity present at the ten-year milestone between the MSC-treated group and the control patients.” Quote from Biologic augmentation of rotator cuff repair with mesenchymal stem cells during arthroscopy improves healing and prevents further tears: a case-controlled study. Although tendon tears are not the same as tendinosis, trials are underway to see if stem cells can help healing in tendinosis as well.