Tendinitis vs. tendinosis: What’s the difference?

You’re visiting the doctor because you’ve had some lingering pain in your shoulder. He says he thinks the culprit might be tendinosis. But what is that?

You’re probably familiar with “tendinitis,” but tendinosis is a lesser-known condition that also impacts the tendons.

While the two conditions are similar in that they deal with tendons, how your condition is treated depends on which condition you have.

So, what’s the difference between the two? Let’s take a look.

Defining tendinitis

Tendinitis, which is also referenced as tendonitis, is an inflammation of the tendon.

But let’s step this back a bit further — what is a tendon? A tendon is a thick, fibrous cord that attaches muscle to bone. When a tendon is inflamed, it can lead to pain and tenderness around a joint.

Tendinitis can occur in any tendon of the body, but is most common around the shoulders, elbows, wrists, knees and heels.

You may be familiar with some of the names for specific types of tendinitis — tennis elbow and pitcher’s shoulder are names commonly used to reference inflammation around the elbow and the shoulder, respectively.

If you develop tendinitis, you’ll likely experience a dull aching sensation when moving the affected area, mild to moderate swelling, and tenderness around the given joint.

In many cases, tendinitis can be treated with self-care, including bracing, icing, over-the-counter anti-inflammatory medications and rest.

Defining tendinosis

While the name is similar to tendinitis, tendinosis is very different. Whereas tendinitis is an acute inflammation of the tendon that causes pain, tendinosis isn’t related to inflammation.

Tendinosis occurs when the tissue of the tendon is degraded. If tendinitis occurs for a long period of time without treatment, tendinosis can develop once the tendon tissue wears down.

Because the tissue is degraded, the symptoms — and the condition — are more serious. If you develop tendinosis, you may experience:

  • Pain in the affected tendon when moved or even touched
  • Stiffness in the tendon and joint
  • Restricted movement
  • A tender lump near the affected area

So, what causes tendinosis? This condition occurs after chronic overuse of a given area. If a tendon is inflamed and doesn’t heal properly, the tissue degrades.

And it’s fairly easy for this to occur. Compared with other parts of the body, tendons take longer to heal because of poor blood supply. If a person doesn’t allow the tendon ample time to heal and continues using the affected tendon, the healing process is further slowed.

On the whole, the condition is more common among those who are middle-aged or older because the tendons are older and more injury-prone. But tendinosis can also occur in athletes and those who perform repetitive movements at work.

If you’re diagnosed with tendinosis, treatment is more intense than the self-care often recommended for tendinitis. Your doctor may recommend a physical therapy regimen, injections and even procedures to help strengthen the tendon and ease the pain.

How doctors tell the difference between tendinitis and tendinosis

If you’re experiencing pain around the tendons, your doctor will talk with you about your symptoms and then perform a physical exam. To make the determination about which condition is causing your pain, he or she may also use a musculoskeletal ultrasound to take a look at the tendons.

If you have tendinitis, the ultrasound will show swelling and inflammation but not microscopic tendon tears or damage.

If you have tendinosis, the ultrasound will show a tendon with noticeable fiber damage and a hard, thickened or scarred appearance.

From there, your doctor will recommend a treatment plan to help get you back to feeling your best. In either case, along with your treatment plan, he or she will also likely recommend changes to your habits, including using an ergonomic keyboard and chair, wearing a brace to support the tendon, performing stretching exercises and even getting massage therapy.

Dr. Jad Dorizas specializes in Sports Medicine and arthroscopic management of a broad spectrum of shoulder, knee and other sports-related injuries. To learn more, please visit Erlanger.org/ortho.