Two types, one tendon — what Achilles tendinopathy actually is

Morning stiffness that eases once you start moving, a dull ache along the back of the leg that flares after a run, or a thickened, tender spot a few centimetres above the heel — these are the hallmarks of Achilles tendinopathy. Rather than acute inflammation, the condition reflects chronic microscopic degeneration within the tendon fibres, which is why it tends to build gradually rather than arriving with a single injury event.

There are two anatomically distinct subtypes, and the difference matters well beyond anatomy.

Noninsertional tendinopathy affects the mid-portion of the tendon, roughly 2–6 cm above where it meets the heel bone. It is the more common form and tends to present in younger, active people — particularly runners — as the fibres in that segment break down with repetitive load over time. This subtype generally responds well to structured physiotherapy loading programmes.

Insertional tendinopathy develops at the bone-tendon junction itself. It sometimes occurs alongside a bony prominence at the back of the heel known as a Haglund's deformity. Because of this anatomical complexity, it can be more resistant to standard eccentric exercise protocols and more likely to require specialist input at an earlier stage.

In both cases, symptoms are localised and activity-related — provoked by exercise, stiff after rest, often worst with the first steps of the morning. This pattern is quite different from the sudden pop, rapid bruising, and loss of push-off associated with a tendon rupture, or from the rest pain and systemic features that might point to something other than a mechanical overuse condition.

Before anything else: ruling out a rupture

One check is worth making before following any tendinopathy pathway: is the tendon still intact?

Achilles tendon rupture is a separate injury — not simply a severe form of tendinopathy — and it requires a fundamentally different response. The distinguishing features are usually unmistakable:

• A sudden, sharp 'pop' felt or heard in the back of the leg during activity
• Immediate inability to push off or rise onto the tiptoes of the affected foot
• Rapid, pronounced swelling and bruising around the heel and lower calf

If any of these features are present, same-day orthopaedic or emergency assessment is needed. A loading programme, stretching routine, or physiotherapy appointment is not the right next step — prompt specialist review is, because the management of a rupture depends on timely diagnosis.

The remainder of this article assumes none of those warning signs apply and that Achilles tendinopathy — the chronic, gradual, activity-related condition — is the working diagnosis.

Physiotherapy first — and what that actually involves

Structured physiotherapy is the right first move for almost every confirmed case — and the word 'structured' is doing real work in that sentence.

The evidence-based treatment is progressive eccentric or heavy-slow resistance loading of the calf-Achilles unit. This is not a stretching routine or a period of rest; it is a graded mechanical stimulus applied consistently over several weeks. Tendons adapt slowly — the tissue remodels under load, but that process cannot be meaningfully compressed or shortcut. A programme typically progresses over ten to twelve weeks, with load increases guided by how symptoms respond rather than by a fixed calendar.

Three months of consistent, well-supervised physiotherapy is the broadly accepted threshold before escalation to further specialist input is considered. That timeframe reflects tendon biology rather than arbitrary caution: if the tissue is not given adequate time under appropriate load, it is genuinely difficult to know whether the problem is the condition itself or an insufficient treatment trial.

A physiotherapist does more than prescribe the loading work. Assessment also covers the factors that drove the tendon into difficulty in the first place — sudden training volume increases, footwear that loads the heel poorly, calf muscle tightness or weakness, or biomechanical patterns that concentrate stress at the tendon. Addressing these alongside the loading programme gives the tendon a better environment to adapt in, and reduces the likelihood of the problem recurring once load is re-introduced.

When a sports medicine physician or MSK consultant becomes the right step

Reaching that three-month mark without meaningful progress is the clearest signal that a different layer of expertise is needed — specifically a sports medicine physician or MSK consultant.

The value of this consultation lies less in any single procedure and more in what it unlocks: a structured reassessment of why recovery has stalled. That typically begins with diagnostic imaging. Ultrasound or MRI can characterise the degree of tendon degeneration — areas of neovascularisation, focal thickening, partial intrasubstance change — and that information shapes what happens next. Imaging at this stage is used to guide management decisions, not to confirm a diagnosis that examination has already established.

For some patients, that assessment leads to a discussion about injectable adjuncts. Options available at this tier include platelet-rich plasma (PRP), peritendinous hyaluronan, and extracorporeal shockwave therapy (ESWT). It is important to be straightforward about the evidence: these treatments may offer benefit for some patients, but current evidence does not support a definitive recommendation for any of them, and outcomes vary considerably between individuals. The 2022 Orthobiologics clinical textbook is explicit that patient expectations must be set carefully — injections of any kind are adjuncts to loading rehabilitation, not substitutes for it. A programme that stops the loading work in favour of a procedure is unlikely to produce durable improvement.

For high-load athletes — competitive runners, in particular — access to this specialist tier need not always wait the full three months. Training modification at a level that protects the tendon whilst preserving conditioning requires clinical oversight that most standard physiotherapy settings are not resourced to provide.

When surgery and an orthopaedic surgeon become relevant

Surgery enters the picture only after a substantive course of nonsurgical management — generally around six months — has failed to produce adequate improvement. That threshold is not arbitrary: it reflects the time needed to exhaust physiotherapy, address load factors, and, where appropriate, trial injectable adjuncts under specialist oversight.

When an orthopaedic referral is made, the relevant subspecialty is a foot and ankle surgeon rather than a general orthopaedic surgeon. The procedures involved are highly specific to the tendon and the surrounding anatomy, and that subspecialty focus matters for both technical execution and realistic outcome expectation.

Surgical options vary by subtype. For noninsertional disease, the main approach is tendon debridement — removing degenerate tissue — sometimes combined with minimally invasive scraping to stimulate healthy repair. For insertional tendinopathy associated with a Haglund's deformity (a bony prominence at the back of the heel that presses on the tendon's attachment point), surgery typically involves removing that prominence alongside debriding the affected tendon tissue. Insertional disease is more likely to reach this stage than noninsertional disease, partly because the bony spur cannot be addressed through loading programmes alone.

Surgery is not a guaranteed resolution. Outcomes depend in part on the degree of tendon degeneration already present, and a structured rehabilitation programme — reloading the tendon progressively — is essential afterwards. Patients considering the surgical route should discuss realistic recovery expectations with their surgeon before deciding.

Atypical symptoms that change the specialist route

Not every presentation follows the standard pathway, and recognising when the route changes is as important as knowing the route itself.

Several features should prompt earlier specialist review — and in some cases, a different type of specialist altogether — rather than starting a standard loading programme:

• Rest pain or night pain unrelated to recent activity, or pain that does not follow the typical stiffness-then-improvement pattern, raises the possibility that the underlying problem is not mechanical overuse.
• Rapid or unexplained swelling, fever, or unintended weight loss alongside tendon symptoms are systemic red flags that require prompt assessment, not a physiotherapy referral.
• Involvement of other joints — alongside or preceding the Achilles symptoms — may point to an inflammatory arthropathy. Psoriatic arthritis and ankylosing spondylitis can both present with Achilles enthesopathy (inflammation at the tendon's insertion), and in these cases a rheumatologist is the appropriate first specialist rather than a physiotherapist or orthopaedic surgeon.
• Recent fluoroquinolone antibiotic use is a recognised risk factor for tendon pathology and should be disclosed to any clinician at the first appointment.
• Visible or palpable nodules on the tendon (xanthomata) may indicate familial hypercholesterolaemia and warrant metabolic assessment alongside — or before — standard MSK management.

Where the underlying cause remains uncertain, early referral is preferable to committing to a lengthy conservative course. Beginning a months-long loading programme when the diagnosis is not firmly established risks delaying the right treatment without offering meaningful benefit.