Achilles Tendinopathy: Symptoms, Causes and Treatment

Achilles tendinopathy is a painful condition of the thick tendon at the back of your ankle, caused by overload and characterised by pain, stiffness and reduced ability to walk, run or jump. Most people improve significantly within three to six months with structured, progressive exercise and load management, supported by the 2024 clinical practice guideline and a 2021 network meta-analysis showing that exercise-based rehabilitation is as effective as more complex treatments.

What is Achilles tendinopathy?

Achilles tendinopathy is a painful overload injury of the Achilles tendon, the thick cord of tissue that connects your calf muscles to your heel bone. It most often affects the middle portion of the tendon, around 2 to 6 cm above where it attaches to the heel, and is caused by repetitive strain that exceeds the tendon's ability to adapt and repair. The tendon becomes painful, stiff and less able to tolerate the loads placed on it during walking, running, jumping or even standing on tiptoe.

The condition was historically called Achilles tendinitis, implying that inflammation was the main problem. However, imaging and tissue studies show that long-standing Achilles tendon pain involves tendon degeneration, disorganised collagen fibres, abnormal blood vessel growth and changes in nerve signalling, rather than classic inflammation. For this reason, the term tendinopathy (meaning tendon disease or disorder) is now preferred and more accurately reflects what is happening inside the tendon.

Achilles tendinopathy is one of the most common lower-limb tendon problems. Research suggests that around 30% of recreational runners will experience it at some point, and it accounts for a significant proportion of presentations to sports medicine and musculoskeletal physiotherapy clinics. It can affect anyone who places repeated load on the Achilles, from competitive athletes to people returning to activity after a period of lower fitness, and it is particularly common in middle age when tendons naturally become less adaptable.

The Dutch multidisciplinary guideline published in the British Journal of Sports Medicine in 2021 defines Achilles tendinopathy as exercise-related Achilles tendon pain combined with impaired function and reduced load capacity, and it emphasises that diagnosis is primarily clinical, based on your history and examination, rather than relying on scans. The guideline notes that imaging changes such as tendon thickening or altered signal on ultrasound or MRI are common in people with no symptoms, so scans are used selectively to rule out other problems rather than to confirm tendinopathy.

"In clinic, I explain to patients that their Achilles has been asked to do more than it was ready for, and now it's stuck in a cycle where it can't tolerate the loads it used to manage easily," says Rachel Pemberton, Clinical Director & Senior Physiotherapist, HCPC registered. "The good news is that tendons can and do adapt when we load them progressively and give them time to rebuild, which is what our rehabilitation programme is designed to do."

What it feels like: symptoms and warning signs

The hallmark symptom of Achilles tendinopathy is pain localised to the back of the ankle, usually in a well-defined area 2 to 6 cm above the heel bone, although some people experience pain right at the heel insertion (insertional tendinopathy). The pain is typically sharp or aching, worse when you press on the tendon, and often accompanied by stiffness, especially first thing in the morning or after sitting for a while. Many people describe a characteristic pattern: the tendon feels stiff and sore when you first start moving, it may ease slightly as you warm up, but then it becomes more painful during or after activity, particularly if you push through.

Common situations that provoke symptoms include:

• First steps in the morning or after rest. The tendon feels tight and painful for the first few minutes of walking.
• Running, especially uphill or on hard surfaces. Impact and push-off load the tendon heavily, and pain often builds during a run or appears afterwards.
• Jumping, hopping or going up on tiptoe. Activities that require the calf and Achilles to generate high force are typically very painful.
• Wearing flat shoes or going barefoot. Shoes with little heel lift place the tendon under greater stretch and load.
• After periods of inactivity. The tendon stiffens when unloaded and hurts when you resume movement.

You may also notice visible or palpable thickening of the tendon (a localised lump or fusiform swelling), tenderness when you squeeze the tendon between your fingers, and sometimes a creaking or grating sensation (crepitus) when you move your ankle. The NHS Lothian self-treatment guide notes that these symptoms are typical and do not necessarily mean the tendon is severely damaged, but they do signal that the tendon is struggling to cope with current load.

In most cases, Achilles tendinopathy develops gradually over weeks or months. However, if you experience sudden, severe pain at the back of the ankle, especially if you heard or felt a "pop" or snap, or if you cannot stand on tiptoe or walk normally, you should seek urgent medical assessment to rule out an Achilles tendon rupture, a different and more serious injury that requires prompt specialist care.

Source: NHS Lothian, Achilles tendinopathy self-treatment guide (2023)

What causes it and who is at risk

Achilles tendinopathy arises when the load placed on the tendon repeatedly exceeds its capacity to adapt and repair. The Achilles tendon is the strongest tendon in the body, but it is also one of the most heavily loaded, transmitting forces many times your body weight during running and jumping. When load is increased too quickly, applied too frequently without adequate recovery, or sustained over a long period in someone whose tendon capacity is reduced, the tendon's internal structure begins to break down faster than it can heal, leading to pain and dysfunction.

The 2021 Dutch guideline divides risk factors into intrinsic (related to your body) and extrinsic (related to training and environment):

Intrinsic risk factors:

• Age. Tendon stiffness and healing capacity decline with age, and Achilles tendinopathy is most common in people aged 30 to 60.
• Previous tendon injury. A history of Achilles problems increases the risk of recurrence.
• Reduced ankle or calf flexibility. Limited ankle dorsiflexion (the ability to bring your shin towards your toes) increases strain on the tendon.
• Calf muscle weakness or imbalance. Weak or fatigued calf muscles shift more load onto the tendon.
• Foot and ankle biomechanics. Excessive foot pronation (rolling in) or a high-arched foot can alter tendon loading patterns.
• Body weight. Higher body mass increases the absolute load the tendon must handle.
• Metabolic and systemic factors. Conditions such as diabetes, high cholesterol and inflammatory arthritis are associated with tendon problems, as are certain medications (notably fluoroquinolone antibiotics, which carry a specific tendon-rupture warning).

Extrinsic risk factors:

• Training errors. Rapid increases in running distance, speed or hill work, insufficient rest between sessions, and sudden changes in activity type (for example starting plyometric training) are the most common triggers.
• Footwear. Shoes with inadequate cushioning, very flat soles or worn-out midsoles can increase tendon load.
• Running surface. Hard surfaces such as concrete and cambered roads place higher impact forces through the tendon.
• Environmental factors. Cold weather can reduce tendon elasticity and increase injury risk.

The British Journal of General Practice review emphasises that Achilles tendinopathy is often multifactorial, with several risk factors combining to tip the balance from adaptation to injury. For example, a middle-aged runner with tight calves who increases weekly mileage by 50% over a fortnight is at much higher risk than a younger, flexible athlete who progresses training gradually.

In my practice at Recover Physiotherapy, I see Achilles tendinopathy across a wide spectrum, from club runners preparing for events such as the Great Bristol Run, to people returning to walking or recreational sport after a break. The pattern is almost always the same: a well-intentioned increase in activity that the tendon was not ready for, combined with one or more of the risk factors above. Identifying and modifying these factors is a core part of the rehabilitation plan.

How it is diagnosed

Achilles tendinopathy is diagnosed primarily from your history and a physical examination. Your clinician will ask about the pattern of your pain (when it started, what makes it better or worse, how it behaves during and after activity), your recent training or activity changes, your footwear, and any relevant medical history or medication. They will then examine your Achilles tendon, looking for localised tenderness, thickening or swelling, and they will assess your ankle range of motion, calf strength and foot biomechanics.

Key clinical tests include:

• Palpation. Pressing along the length of the tendon to identify the exact site of tenderness, which is usually well localised in midportion tendinopathy.
• Arc sign. The tender area moves up and down as you move your ankle, confirming that the pain is in the tendon itself rather than surrounding structures.
• Calf raises. You will be asked to perform single-leg heel raises (going up on tiptoe on one foot), which typically reproduce pain and often reveal weakness or reduced endurance compared with the other side.
• Ankle dorsiflexion range. Your clinician will measure how far your ankle can bend, as reduced dorsiflexion increases tendon strain.

Imaging is not routinely needed to diagnose Achilles tendinopathy. The 2024 clinical practice guideline notes that ultrasound and MRI can show tendon thickening, abnormal tissue signal and increased blood flow (neovascularisation), but these findings are also common in pain-free tendons, so they do not predict symptoms or guide treatment in most cases. Imaging may be requested if there is diagnostic uncertainty (for example to rule out a partial tear, bursitis or bone problem), if symptoms are atypical, or if you are not improving as expected after several months of rehabilitation.

X-rays are occasionally used to check for calcification within the tendon or bone spurs at the heel attachment (common in insertional tendinopathy), but they do not show the tendon tissue itself. Blood tests are not part of routine assessment unless there is concern about a systemic condition such as inflammatory arthritis or metabolic disease.

The British Journal of General Practice guide advises GPs to refer patients for physiotherapy or specialist assessment if pain is severe, if there is significant functional limitation, or if symptoms have not improved after three months of initial self-management, and it recommends urgent referral if an Achilles rupture is suspected (sudden severe pain, inability to stand on tiptoe, palpable gap in the tendon).

How Achilles tendinopathy is treated

The cornerstone of treatment for Achilles tendinopathy is progressive, high-load exercise combined with education and load management. A 2021 living systematic review and network meta-analysis published in the British Journal of Sports Medicine pooled data from 29 randomised controlled trials and found that most active treatments, including exercise therapy alone, injection therapy, shockwave therapy and various combinations, were superior to a wait-and-see approach at three months, with improvements of around 15 to 35 points on the VISA-A (Victorian Institute of Sport Assessment–Achilles) scale, a 100-point questionnaire where higher scores mean better function. Critically, the network meta-analysis found no clear difference between most active treatments, meaning that exercise-based rehabilitation performs as well as more complex or costly interventions for the majority of patients.

A 15-point change on VISA-A is considered the minimal important difference. Positive values favour active treatment. Source: O'Neill et al., BJSM 2021

Exercise-based rehabilitation

The 2024 clinical practice guideline gives its strongest recommendation to tendon-loading exercise, stating that clinicians should prescribe progressive, high-load resistance training as first-line treatment for midportion Achilles tendinopathy. The guideline is supported by moderate to high-quality evidence showing that structured exercise programmes reduce pain and improve function, with effect sizes comparable to or better than passive treatments or injections.

Two main exercise approaches are used:

• Eccentric loading. The landmark 1998 study by Alfredson and colleagues demonstrated marked pain reduction and return to activity in patients with chronic Achilles tendinopathy using a 12-week programme of eccentric heel drops (lowering your heel below the level of a step while standing on one leg). This protocol formed the basis for modern tendon rehabilitation and remains widely used.

• Heavy slow resistance (HSR) training. More recent research shows that progressive resistance exercises using higher loads and slower movement speeds (for example weighted calf raises performed with both legs and then progressing to single-leg work) are equally effective and may be better tolerated by some patients. The key principle is that the tendon must be loaded heavily enough to stimulate adaptation, which typically means working at a load you can lift for around 6 to 12 repetitions before fatigue.

Your physiotherapist will design a programme tailored to your current pain and function level, starting with exercises you can manage and progressively increasing the load, volume and complexity over weeks and months. The Journal of Physiotherapy review emphasises that rehabilitation is not a one-size-fits-all protocol, it is an individualised, monitored process that adjusts based on your response, and it typically includes:

1. Initial load management. Temporarily reducing or modifying aggravating activities (for example reducing running volume or switching to cycling) to bring pain to a tolerable level.
2. Isometric exercises. Holding a calf-raise position without movement, which can reduce pain in the short term and is a useful starting point if you are very sore.
3. Progressive strengthening. Gradually introducing eccentric or HSR exercises, increasing resistance as tolerated.
4. Functional retraining. Adding exercises that mimic your goal activities (hopping, running drills, sport-specific movements) once strength and pain allow.
5. Return to activity. A structured, incremental plan to resume running, sport or other high-load tasks, monitoring symptoms and adjusting load as needed.

Pain during exercises is common and, within limits, acceptable. The guideline and clinical consensus suggest that pain up to around 3 to 5 out of 10 during exercise, which settles within 24 hours and does not cause a significant increase in morning stiffness, is safe and may even be necessary for optimal tendon adaptation. Your clinician will help you understand what level of discomfort is expected versus concerning.

Education and self-management

Understanding your condition and how to manage load is as important as the exercises themselves. The Journal of Physiotherapy review identifies patient education as a core component of physiotherapy management, covering:

• What tendinopathy is (a load-capacity mismatch, not damage or inflammation that requires complete rest).
• Why exercise works (progressive loading stimulates tendon remodelling and increases load tolerance).
• How to monitor symptoms (using pain and function as guides to adjust activity, not as absolute stop signals).
• Training principles (the importance of gradual progression, adequate recovery and avoiding load spikes).
• Long-term self-management (continuing maintenance exercises and being alert to early warning signs if you increase activity again).

At Recover Physiotherapy, education is woven into every session. I find that once patients understand that their tendon is not fragile and that controlled loading is therapeutic rather than harmful, their confidence improves and they engage more fully with the rehabilitation plan.

Adjunct treatments

Several additional treatments are used alongside exercise, particularly for patients with high pain levels or those who have not responded to exercise alone:

• Shockwave therapy. Extracorporeal shockwave therapy (ESWT) delivers high-energy sound waves to the tendon, which may stimulate healing and reduce pain. A 2009 systematic review concluded that ESWT provides clinically relevant short- to medium-term improvements in chronic Achilles tendinopathy, especially when combined with eccentric loading, although the optimal dose and protocol remain debated.

• Corticosteroid injection. A 2022 randomised controlled trial published in JAMA Network Open found that adding an ultrasound-guided corticosteroid injection to exercise therapy produced greater short-term improvements in pain and function than exercise plus placebo injection. However, the long-term balance of benefit and risk is still being evaluated, and injections are typically reserved for cases where pain is limiting engagement with rehabilitation. The Dutch guideline notes that corticosteroid injections carry a small risk of tendon weakening or rupture and should be used cautiously.

• Platelet-rich plasma (PRP) and other biological injections. The evidence for PRP in Achilles tendinopathy is mixed, with some trials showing modest benefit and others no difference compared with placebo. The 2024 guideline does not recommend PRP as a routine treatment.

• Manual therapy and soft-tissue techniques. Hands-on treatment such as massage, myofascial release or joint mobilisation may help with associated calf tightness or ankle stiffness, but the guideline notes that evidence for manual therapy as a standalone treatment is limited, and it is best used to support the exercise programme.

• Orthotics and heel lifts. Shoe inserts or heel wedges can temporarily reduce tendon strain by altering foot position or adding a small heel raise, which may be helpful in the early stages or for people with significant biomechanical factors. However, they are not a substitute for strengthening and should be weaned as the tendon improves.

• Night splints. Splints that hold the ankle in a stretched position overnight were popular in the past, but the network meta-analysis found that adding a night splint to exercise did not produce a clear additional benefit, and many patients find them uncomfortable.

The 2021 Dutch guideline emphasises that adjunct therapies should not replace exercise-based rehabilitation, they are add-ons that may help specific patients or situations, and their use should be discussed and agreed on an individual basis.

Surgery

Surgery is considered only for patients who have not improved after at least six months of high-quality conservative treatment. The British Journal of Sports Medicine treatment algorithm proposes a stepwise approach, with surgery as the final option for recalcitrant cases. Surgical procedures include debridement (removing damaged tissue), tendon stripping (excising abnormal blood vessels and nerve tissue), or, in severe cases, tendon transfer or reconstruction. Outcomes are variable, and post-operative rehabilitation is lengthy, so surgery is reserved for a small minority of patients. The StatPearls overview notes that most people improve with conservative care and never need surgery.

What recovery looks like and how long it takes

Recovery from Achilles tendinopathy is typically measured in months, not weeks. The NHS Lothian guide states that most people improve within six months of starting structured self-management or physiotherapy, although some take up to 12 months, and a proportion of cases remain symptomatic beyond that. The 2021 network meta-analysis reports that meaningful improvements in pain and function are often evident by three months, but full return to pre-injury activity levels and confidence usually takes longer.

A realistic recovery trajectory might look like:

• Weeks 0 to 2. Initial assessment, pain and load management, starting isometric and light strengthening exercises. Pain may remain high but should not worsen.
• Weeks 2 to 6. Progressive loading introduced, pain during and after exercises is expected but should be within agreed limits. Morning stiffness and day-to-day pain often start to ease.
• Weeks 6 to 12. Strengthening continues, functional exercises added, gradual return to modified activity (for example walk-run programmes). Many patients feel significantly better by this stage.
• Months 3 to 6. Continued progression towards full activity, monitoring for setbacks, refining load management. Most people achieve their main functional goals during this period.
• Months 6 to 12. Maintenance phase, addressing any remaining deficits, returning to higher-level sport or activity. A small proportion of patients plateau and may consider adjunct treatments or specialist review.

Progress is rarely linear. Flare-ups are common, especially if you increase load too quickly or encounter an unexpected spike (a long walk, a return to running, a change in footwear). The key is to recognise a flare-up early, adjust load temporarily, and then resume progression once symptoms settle. Your physiotherapist will teach you how to self-manage these fluctuations.

The British Journal of General Practice guide advises that if symptoms are severe or not improving after three months of appropriate management, referral for specialist physiotherapy, sports medicine review or imaging should be considered to ensure the diagnosis is correct and explore whether adjunct treatments or a different rehabilitation approach might help.

In my experience working with runners at Bristol & West Athletics Club and providing event medical cover at the Great Bristol Run, the patients who recover most successfully are those who commit to the exercise programme, adjust their training intelligently, and accept that tendon rehabilitation is a slow process that rewards patience and consistency rather than quick fixes.

When to seek urgent help

Most Achilles tendon pain is not an emergency, but certain symptoms require prompt medical assessment:

• Sudden, severe pain at the back of the ankle, especially if you heard or felt a "pop" or snap. This may indicate an Achilles tendon rupture, a serious injury that needs urgent specialist care.
• Inability to stand on tiptoe or push off with the affected foot. This suggests significant tendon damage or rupture.
• A palpable gap or defect in the tendon. If you can feel a distinct hollow or step in the tendon, seek immediate assessment.
• Severe swelling, redness or warmth, especially if accompanied by fever or feeling unwell. These symptoms could indicate infection or inflammatory arthritis rather than simple tendinopathy.
• Sudden worsening of pain after a corticosteroid injection. Although rare, tendon rupture can occur after injection, and sudden severe pain should be assessed urgently.

If you experience any of these, contact your GP, attend an urgent care centre or go to A&E. For routine Achilles tendon pain that is not improving with self-management after six weeks, arrange an appointment with a physiotherapist or your GP for assessment and a structured treatment plan.

Common questions about Achilles tendinopathy

Will exercises make my tendon worse or cause it to rupture?

Some discomfort during and after exercises is expected and is a normal part of tendon adaptation, but the programme is designed around "acceptable" pain levels that settle within 24 hours. Research, including the 2024 clinical practice guideline, indicates that progressive loading, when sensibly progressed, helps the tendon adapt and strengthen rather than damage it. Rupture is a recognised complication in Achilles disorders, but it is uncommon when exercises are introduced gradually and heavy, sudden overloads are avoided. Structured rehabilitation is designed to reduce your rupture risk over time by improving tendon strength and control, and you will be monitored for any warning signs. Your clinician will adjust the plan if pain is too intense or lingers beyond the expected timeframe.

How long before I can run or play sport normally again?

Many people feel meaningful improvement within three months, especially with consistent exercises and load management, although full recovery can take several months and a proportion of cases remain symptomatic longer. The 2021 network meta-analysis and NHS Lothian guide both note that typical recovery windows are three to six months for significant improvement, with some people taking up to 12 months. Your clinician will set realistic milestones, such as returning to walking without pain, then progressing to jogging, then full running volume, and will review progress regularly so expectations and goals are clear. Return to sport is individualised and depends on your symptoms, strength and confidence, not a fixed calendar date.

I have tried resting already, why would physiotherapy be any different?

Pure rest often gives short-term relief but does not improve the tendon's ability to cope with load, which is why symptoms frequently return when activity resumes. The Journal of Physiotherapy review and 2024 guideline emphasise that the tendon needs progressive loading to adapt and strengthen, not prolonged unloading. Physiotherapy focuses on building the tendon back up with planned, gradually increasing exercises, education about load management, and, if needed, adjunct therapies such as shockwave or injections, targeting the underlying load intolerance rather than just calming pain. It is an active, monitored process rather than passive rest.

Do I have to stop all my sport or activity while I do this?

Total rest is rarely needed. Instead, activities are usually modified, for example shorter runs, reduced jumping volume, or switching temporarily to lower-impact options such as cycling or swimming, while you build strength through rehabilitation. The British Journal of Sports Medicine treatment algorithm and Dutch guideline both recommend relative rest and load modification rather than complete cessation of activity. Together with your clinician, you will agree a plan that protects the tendon from overload spikes but keeps you as active as safely possible, adjusting the balance as your tendon improves.

Are shockwave therapy, injections or other treatments better than exercises?

The 2021 network meta-analysis found that multiple active treatments, including exercise alone, produced similar improvements at three to 12 months, with no single therapy clearly superior. Adjuncts such as shockwave or corticosteroid injections may help specific patients or provide short-term symptom relief, especially if pain is limiting your ability to engage with exercises, but they work best on top of, not instead of, a high-quality loading programme. The 2024 guideline gives the strongest recommendation to progressive exercise, with moderate evidence for combined approaches. Marketing of advanced devices or injections can make them sound curative, so it is understandable to overestimate their impact, but the evidence shows that structured rehabilitation is the foundation of treatment.

Is Achilles tendinopathy just inflammation, and will anti-inflammatory tablets or rest cure it?

Imaging and histology show that chronic Achilles tendinopathy mainly involves tendon degeneration, disorganised collagen, and abnormal blood vessel and nerve growth, not purely acute inflammation. The StatPearls overview and Dutch guideline both explain that the term tendinopathy (tendon disorder) has replaced tendinitis (tendon inflammation) because inflammation is not the dominant process. While short courses of anti-inflammatory medication or rest can help pain in the early stages, they do not rebuild tendon strength or load tolerance, which is why progressive loading and rehabilitation are needed to restore function. This misconception is understandable because older terminology used "tendinitis", which suggests inflammation only.

Will I need surgery if physiotherapy does not work?

Most people improve with well-structured conservative management and never need surgery. The British Journal of Sports Medicine algorithm and StatPearls overview both note that surgery is reserved for the small proportion of patients who have not responded to at least six months of high-quality exercise-based rehabilitation, education and, where appropriate, adjunct treatments. Even in chronic cases, exercise programmes and selected therapies can significantly reduce pain and improve function. Surgery carries its own risks and requires lengthy post-operative rehabilitation, so it is always a last resort after thorough non-operative care. It is understandable to assume surgery is the "definitive" option, particularly if you know others who have had operations, but the evidence supports conservative treatment as first line for the large majority.

What can I do myself to help recovery?

Self-management is central to recovery. The NHS Lothian guide recommends relative load modification (reducing or adjusting aggravating activities temporarily), starting a progressive calf-loading exercise programme, wearing supportive footwear with a small heel (avoiding very flat shoes or going barefoot for long periods), and applying ice after activity if it helps with pain. Avoid sudden increases in training volume or intensity, and be patient, as tendon adaptation takes weeks and months. If you are not improving after six weeks of self-management, seek advice from a physiotherapist or podiatrist for a structured assessment and tailored rehabilitation plan. Keeping a simple symptom and activity diary can help you and your clinician identify patterns and adjust your programme effectively.

This article is for general information only and is not a substitute for professional medical advice. If you have concerns about your health, please contact your GP or physiotherapist for a personal assessment.

This article is for general information only and is not a substitute for personal medical advice. If you have concerns about your health, please consult a qualified clinician or your GP.