Why the distinction matters before you do anything else

Achilles pain can stem from two very different problems — a chronic overuse condition called tendinopathy, or an acute structural tear known as a partial rupture — and the right management for one can be the wrong choice for the other.

The difficulty is that the two conditions share enough features to blur the picture. Both produce pain and stiffness at the back of the ankle, and a partial rupture that is treated as simple tendinopathy may go unrecognised for weeks. Loading a partly torn tendon without appropriate rest or imaging surveillance carries a meaningful risk of converting the partial tear into a complete rupture — an outcome that typically requires surgery and a far longer recovery.

Getting the diagnosis right before starting any treatment programme is therefore the first decision in the pathway. It determines whether physiotherapy alone is appropriate, whether imaging is needed urgently, and whether a consultant assessment should happen sooner rather than later. As Gatz et al. (2020) noted, partial ruptures occupy a clinical grey zone between tendinopathy and complete tears, and are frequently missed on first presentation.

How each condition actually feels

The symptom pattern is often the clearest early clue, even before any examination takes place.

If your pain came on gradually

Tendinopathy tends to announce itself slowly — typically over weeks or months of increased activity. The characteristic feeling is a dull ache or stiffness at the back of the ankle, worst with the first few steps in the morning or after a long period of sitting, and noticeably easier once the tendon has warmed up. Running through it, at least initially, may feel possible. On the tendon itself, a thickened or nodular area is common, usually sitting roughly 2–6 cm above where the tendon meets the heel bone. Crucially, most people with tendinopathy can still walk normally and complete a double-leg calf raise, even if it produces some discomfort (Matthews et al., 2021).

If your pain came on suddenly

A partial rupture is usually tied to a specific moment: a sprint, a jump, a sudden push-off. Many people describe a 'pop' or 'snap' at the back of the calf, sometimes accompanied by a sensation of being struck. Sharp, localised pain follows immediately, along with swelling and, in some cases, bruising that develops over hours. The functional impact is the most telling sign — difficulty pushing off the foot, trouble rising onto the toes, and an inability to complete a single-leg calf raise all point strongly toward a structural tear rather than tendinopathy alone. Testing this on the uninjured side first provides a useful comparison.

One important caution: not every partial rupture produces a dramatic pop. Some tears have a quieter onset — moderate pain, mild swelling, and only partial functional loss — which is precisely why Gatz et al. (2020) described them as a neglected entity frequently confused with tendinopathy. A muted presentation does not mean the tendon is intact.

On palpation, a focal tender 'gap' or divot at a specific point on the tendon is more consistent with a rupture; diffuse, fusiform thickening across a broader segment is more consistent with tendinopathy. Either way, a clinical test alone is not a verdict — the next step explains why imaging matters when the picture is uncertain.

What a clinical assessment involves

Knowing what each test measures — and where it falls short — helps explain why a single examination finding rarely settles the question on its own.

The Thompson test

The Thompson (calf squeeze) test is the most widely recognised Achilles assessment. With the patient lying prone, a clinician squeezes the calf muscle; if the foot fails to plantarflex, a complete tendon rupture is likely. The test achieves 96–100% sensitivity and 93–100% specificity for complete ruptures. Its critical limitation, however, is that it is typically negative in both tendinopathy and partial ruptures, where enough fibres remain intact to transmit some force. A normal Thompson test does not exclude a partial tear.

Functional and load-based tests

For tendinopathy, clinicians use a different toolkit. Tenderness and thickening on palpation, single-leg heel-raise capacity, and discomfort provoked by hopping or stair climbing each help gauge the severity of load-related symptoms (Matthews et al., 2021). A physiotherapist may also use a short questionnaire — the VISA-A — which asks ten questions about how much daily activity and sport the pain is limiting; completing it takes roughly two minutes and gives a reproducible baseline against which to measure progress week by week.

When imaging is needed

Clinical examination can narrow the differential considerably, but it cannot reliably map the extent of fibre disruption in a suspected partial rupture. Ultrasound or MRI provides that structural detail, confirming whether a tear is present and informing decisions about load management or onward referral. One important caveat applies: tendons frequently show signal changes on imaging in the absence of any symptoms. An incidental finding on a scan is not automatically a diagnosis — the clinician weighs it alongside the history, functional tests, and examination findings, rather than treating it as a verdict in isolation.

When the diagnosis stays unclear

Both advanced tendinopathy and a partial rupture share the same underlying tissue problem: chronic inflammation and structurally disorganised collagen. Research published in the British Journal of Sports Medicine (Dakin et al., 2018) found that this inflammatory profile is common to degenerative and traumatically injured tendons alike. At the microscopic level, tissue from an overloaded tendinopathic tendon and tissue from one that has partially torn can look remarkably similar — which explains why a patient with long-standing tendinopathy who then sustains a small incremental tear may have no clear moment of injury to report.

For the reader, the practical implication is straightforward: if symptoms do not fit neatly into one pattern after working through the sections above, that uncertainty is not a sign that something is being missed. It reflects a genuine biological overlap that examination findings alone cannot always disentangle. When that is the case, pursuing imaging before committing to any rehabilitation programme is more reliable than treating by best guess — and deciding who should order, interpret, and act on those images is where specialist input becomes essential.

Which specialist to consult and when

Matching the right specialist to the right stage of the problem is more straightforward than it might appear — though the appropriate starting point depends on how confident the diagnosis already is.

Physiotherapist

For a presentation that fits classic tendinopathy — gradual onset, preserved function, no suspicion of a structural tear — a physiotherapist is generally the right first contact. UK patients can self-refer to NHS physiotherapy without a GP referral, which removes a step many people don't realise they can skip.

Podiatrist

Where biomechanical factors appear to be driving or sustaining the problem — flat-footedness, gait asymmetry, or inadequate footwear — a podiatrist may be the more useful starting point or a productive parallel referral. Podiatrists can assess lower-limb mechanics, prescribe custom orthotics, and in many clinics offer shockwave therapy.

Sports medicine physician

A sports medicine physician is well-placed to oversee non-operative management across both conditions: load-progression planning, injection therapy where appropriate, and structured return-to-sport criteria that go beyond a fixed timeline.

Orthopaedic foot-and-ankle surgeon

Surgical assessment becomes relevant when conservative care has not produced adequate recovery after a reasonable trial, when imaging has confirmed a significant partial rupture that is not settling, or when surgical repair is under active consideration. At that point, a foot-and-ankle orthopaedic surgeon is the appropriate referral.

If rupture has not been ruled out

When there is real uncertainty about whether a partial tear is present, it is worth seeking an assessment with imaging before starting any rehabilitation programme, rather than defaulting to physio-first on the assumption the tendon is intact.

Search MSK lists physiotherapists, podiatrists, sports medicine physicians, and orthopaedic foot-and-ankle surgeons across the UK — filter by specialty and region to find a suitable specialist for your situation.

Recovery: what to expect from each condition

Recovery timelines differ considerably between the two conditions — and within each, how much you ask of the tendon shapes how long the process takes.

Achilles tendinopathy

Tendinopathy responds to progressive loading rather than rest. Eccentric calf exercises — lowering the heel slowly below step level, typically performed twice daily over several weeks — are among the best-evidenced approaches. Improvement is gradual, and symptom flares during early rehabilitation are common; they are a feature of the adaptation process rather than a sign that rehabilitation is failing. Most people see meaningful change over weeks to months, though stubborn cases can take longer.

Partial rupture

Mild-to-moderate partial tears typically recover without surgery in four weeks to six months, depending on the extent of the tear and physical demands. Severe partial tears, or tears in athletes returning to high-load sport, may require six to twelve months and sometimes surgical repair followed by structured rehabilitation.

Return to sport

For both conditions, the point at which it is safe to return to full activity is decided by criteria rather than by a date on a calendar. Practical markers include completing a pain-free single-leg calf raise, achieving comparable strength symmetry between limbs, and tolerating a graded reintroduction of running load — for example, jogging intervals before sustained running — without a symptom flare. A sports medicine physician or physiotherapist can oversee this progression.

Recurrence risk

Both conditions carry a real recurrence risk if the load management, biomechanics, or training patterns that contributed to the original injury are not addressed as part of recovery.