Tendonitis vs Tendinosis: What You Need to Know

tendonitis vs tendinosis
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For a medical condition that’s so widespread it’s surprising how misunderstood tendonitis is and how often we actually refer to tendonitis what is actually tendinosis.

Say tendonitis to someone and they know what you mean. Say tendinosis on the other hand and watch them raise their little eyebrows.

So what is the difference between these two conditions and how do you differentiate them? We have a quick look.

Tendons and Tendinopathies

Tendons are super thick collagen based tissues that tie your muscles to the bone. 

They need to be tough to put up with all the strain placed on them when muscles contract.

When they get injured it’s referred to as a tendinopathy. “Tendon” – tendon, “pathy” – problem with. Tendonitis and tendinosis are both tendinopathies.

What Is Tendonitis

achilles tendonitis vs tendinosis

When tendons become specifically inflamed and irritated through injury it’s called tendonitis. Micro-tears appear in the tissue leading to inflammation. The presence of inflammation here is crucial.

It can cause swelling, acute pain, discomfort and tenderness, making it difficult to move the affected joint.

It can happen in any tendon but is most commonly in the shoulders, elbows, wrists, knees and heels. These conditions often go by different names:

  • Swimmer’s shoulder
  • Jumper’s knee
  • Pitcher’s shoulder
  • Golfer’s elbow/Climber’s elbow
  • Tennis elbow

What Is Tendinosis

elbow tendonitis from climbing

As opposed to an acute injury, tendinosis is a gradual degeneration of the tendon tissue over time. This is in response to overuse through repetitive strains, without the tendon having time to recover.

It’s caused by chronic overuse and occurs in the same joints as tendonitis. In fact, it’s now thought that most cases of tendonitis are actually tendinosis.

Tendonitis vs Tendinosis: Key Differences

tendonitis vs tendinosis

Tendonitis results from microtears that appear when the muscle is too heavily loaded. This leads to inflammation, ergo the “itis” part of the name.

Tendinosis in comparison is the chronic counterpart when the tendon is continually strained. It isn’t able to recover leaving it in a degenerative state where it isn’t able to correctly heal. There is no inflammation in tendinosis, which is the key distinction.

As tendinosis is chronic and results in the tendon being in a continued degraded state, it is consider more serious than tendonitis.

Tendonitis vs Tendinosis: Typical Examples

The common culprits are:

  • Lateral epicondylitis. Aka tennis elbow. This is pain on the outside knobbly part of your elbow. Do you actually get it from tennis? You can do. Do you only get it from tennis? No. Bad desk ergonomics is a common cause. 
  • Medial epicondylitis. Aka golfer’s/climber’s elbow. This is pain on the inside knobbly part of your elbow. You can get this from any grip intensive repetitive action.
  • Rotator cuff tendonitis. This one has lesser known fancy names.  It’s a shoulder disorder with inflammation of the main shoulder capsule and related tendons.

Symptoms of Both

The pain from both are pretty much identical and it can be difficult to differentiate between tendonitis or tendinosis based solely on physical examination.

A usual indicator of which deadly version you have is given by how long you’ve had the condition. Many suffers of tendinitis have had the condition on and off for years. Sounds more like a chronic condition right?


The causes of both tendonitis and tendinosis is repetitive action. Performing the same action over and over, in sports or otherwise.

Tendinosis is then caused by the chronically overusing the tissue. Tendons take an extremely long time to heal due to their poor blood supply and therefore straining them before they have been able to heal lead can lead to chronic conditions.

Both forms can occur in people who:

  • Perform sports at an intense level and don’t recover enough.
  • Perform continuous repetitive tasks.
  • Have un-recovered tendonitis.

Diagnosis of Tendonitis vs Tendinosis

ultrasound for tendonitis and tendinosis diagnostics

A physical exam where pain is elicited through specific positions will give a positive diagnosis. The usual prodding and twisting!

Often an ultrasound with Doppler scanner is used to confirm this diagnosis. If you see your tendon light up in red and blue then congratulations you have a tendinopathy!

For serious chronic conditions which struggle to heal, X-rays or MRI’s may also be used to eliminate any other possibilities.

Departing Thoughts on Tendonitis and Tendinosis

Both tendonitis and tendinosis are tendinopathies, painful conditions arising from tendons which have been pushed, pulled or torn a little too much.

Tendonitis is acute and more short term. Tendinosis is the chronic and more serious counterpart.

Research now believes that in most cases what we think or thought was tendonitis is actually tendinosis.

Tell us about your experience with tendinopathies and how you overcame them?

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