Tendon pain (tendinopathy): what happens in the tendon and how is it loaded?

Tendinopathy is described as a multifaceted condition of the tendon with pain, reduced function and reduced tolerance for activity [3]. The most common sites of overuse are the rotator cuff in the shoulder, the attachments at the elbow, the patellar tendon, tendons in the gluteal muscles and the Achilles tendon [3].

The pain is typically localised to the tendon or its attachment and comes with loading [1]. You can read about some of the conditions on the pages about rotator cuff problems, tennis elbow and jumper's knee, and in the article about Achilles tendon pain.

NHI writes that the condition is not caused by bacteria or viruses, and that professionals often prefer the terms tendinopathy and tendinosis, since long-standing problems often involve little inflammation in the tendon [5].

A model from 2009 describes three stages: reactive tendinopathy, tendinopathy with failed repair and degenerative tendinopathy [1]. The first stage is a short-term reaction to acute overload, where the tendon can become thicker and stiffer, and it can return to normal if the load is reduced or recovery is adequate [1]. In the last stage there is cell death and disorganised tissue, and the tendon has little capacity to return [1].

The model has since been questioned. The authors of a 2016 review point out that classifying by tissue structure is disputed in a condition that is primarily a pain condition [2]. Pain and tissue changes do not always go together either. Some tendons with changes cause no pain, and some tendons that look normal are painful [1].

Loading is regarded as the main driver in the model, especially in the early stages [1]. Healthy tendons adapt to load as their structure and mechanical properties change [4]. How much, how hard and how often the tendon must be loaded before problems arise is not clearly defined [1]. Time between loading sessions appears to matter for the tendon to be able to adapt [1].

Individual factors such as age, sex, body composition and biomechanics affect how the tendon tolerates load [1]. In the early stages it can help to reduce or change the load, for example its intensity, frequency or type [1]. Loading where the tendon works like a spring, such as hopping and fast running with little rest between sessions, may aggravate the problems in these stages, while cycling and strength training can often continue [1].

The diagnosis is made mainly clinically, from the history and an examination. Pain-provoking tests or imaging are used in some cases [3]. For tendon pain in the shoulder, NHI describes that the history often raises suspicion of the diagnosis, and that a systematic test of shoulder mobility can show which tendon is involved [5].

Imaging has limitations. It is not yet possible to clearly distinguish tissue changes that cause pain from those that do not, and imaging findings are a weak predictor of how treatment will go [4]. X-ray is usually not necessary for tendon pain in the shoulder [5].

Treatment includes various exercise and loading programmes, other measures and, in some cases, surgery. The authors of a 2021 review write that the effect of the different options is still unclear [3]. A 2013 review refers to a study of rotator cuff problems where specific loading exercises with an eccentric component gave better function than a programme of range-of-motion exercises [4].

NHI describes that rehabilitation of the shoulder should be gradual, with exercises for mobility and later strength, and that one should start with light load and many repetitions [5]. Activity should be adjusted and movements that provoke pain avoided, but the arm should not be held completely still [5]. For Achilles problems NHI recommends eccentric exercises [6].

A corticosteroid injection can have a short-term effect [4][5]. NHI normally does not recommend corticosteroids for problems in the Achilles tendon, because they can weaken the tendon [6]. Shockwave therapy is mentioned for calcific deposits in the shoulder [5], and for Achilles problems it can have an effect on pain during the first year [6].

It varies with which tendon is involved and how long the problems have lasted. NHI writes that acute conditions in the shoulder usually respond well, while repeated or little-treated tendon problems can lead to long-standing symptoms [5]. For Achilles problems, rehabilitation often takes several months [6].

Problems that do not improve, or that get worse, should be assessed again. Tendon rupture is rare but can occur when the tendon is weakened [6]. If you get sudden severe pain and lose function in a tendon, you should contact a doctor.

For work-related problems in the shoulder, adjustments at work or sick leave may be relevant [5].

A physiotherapist can examine where the pain is, what triggers it and how the tendon is loaded in daily life, at work and in training, and together with you make a plan for rehabilitation. When the diagnosis is uncertain, diagnostic ultrasound may be relevant. You can read more about physiotherapy at Dr.Dropin.

What is tendinopathy?

Tendinopathy is a condition of the tendon with pain, reduced function and reduced tolerance for activity. It is linked to loading [1][3].

Is tendonitis the same as tendinopathy?

The terms are often used for the same thing. Professionals still prefer tendinopathy, since long-standing problems often involve little inflammation in the tendon [5].

Should I rest when my tendon hurts?

NHI recommends adjusting activity and avoiding movements that provoke pain, but not keeping the shoulder completely still [5]. In the early stages it can help to reduce or change the load [1].

Do I need an MRI or ultrasound for tendon pain?

The diagnosis is made mainly clinically. Imaging is used in some cases, and the findings must be interpreted together with the symptoms [3][4].

How long does tendon pain last?

It varies. Acute problems often respond well, while repeated or little-treated problems can last a long time [5]. For Achilles problems, rehabilitation often takes several months [6].

The article about Achilles tendon pain describes one of the most common tendon conditions in more detail. You can find more articles in the overview of articles.

This article was written by Dr.Dropin Fysikalske and is based on the sources listed below. It gives general information and does not replace an examination by a healthcare professional.

The websites were accessed and read on 22 October 2026.

1. Cook JL, Purdam CR. Is tendon pathology a continuum? A pathology model to explain the clinical presentation of load-induced tendinopathy. Br J Sports Med. 2009;43:409-416. doi:10.1136/bjsm.2008.051193. Link

2. Cook JL, Rio E, Purdam CR, Docking SI. Revisiting the continuum model of tendon pathology: what is its merit in clinical practice and research? Br J Sports Med. 2016;50(19):1187-1191. doi:10.1136/bjsports-2015-095422. Link

3. Millar NL, Silbernagel KG, Thorborg K, Kirwan PD, Galatz LM, Abrams GD, et al. Tendinopathy. Nat Rev Dis Primers. 2021;7:1. doi:10.1038/s41572-020-00234-1. Read as abstract. Link

4. McCreesh K, Lewis J. Continuum model of tendon pathology - where are we now? Int J Exp Pathol. 2013;94(4):242-247. doi:10.1111/iep.12029. Link

5. Senebetennelse i skulderen (tendon inflammation in the shoulder). NHI.no. Last updated 15 October 2024. Link

6. Akillessenebetennelse (Achilles tendonitis). NHI.no. Last updated 15 October 2024. Link