Achilles Tendinopathy: Pain at the Back of the Heel, Explained

If the back of your heel is stiff and sore — worst when you first get going, and flaring after a run or a busy spell on your feet — Achilles tendinopathy is a likely culprit. It is one of the most common overuse injuries in the lower leg, especially among runners and people who have recently increased their activity. The good news is that it responds well to the right kind of exercise; the catch is that it is slow, and a couple of well-meant treatments can actually make it worse. Here is what is going on and what genuinely helps. For the bigger picture, see our foot and heel pain guide.

What is Achilles tendinopathy?

The Achilles is the thick, strong tendon connecting your calf muscles to your heel bone — it is what lets you push off, run, and rise onto your toes. Achilles tendinopathy is an overuse problem in that tendon: repeated loading outpaces the tendon's ability to repair, and the tissue becomes painful, sometimes thickened. It comes in two main forms — mid-portion (a few centimetres above the heel, the more common type) and insertional (right where the tendon meets the heel bone). The "-opathy" ending matters: this is now understood as a problem of tendon overload and failed healing rather than simple inflammation, which is exactly why anti-inflammatory shortcuts tend to disappoint.

Why it happens

Achilles tendinopathy is the classic "too much, too soon" injury. Common contributors include:

• A sudden jump in training — more distance, more hills, more speed, without time to adapt.
• Tight or weak calf muscles, which throw extra strain onto the tendon.
• Footwear changes or worn-out shoes.
• Age — tendons become a little less forgiving over time.

It is genuinely common: estimates put the incidence at around one in ten in the running population ¹, which is why it is such a familiar complaint in active adults.

What it feels like

• Morning stiffness and soreness at the back of the heel or just above it.
• Pain at the start of activity that may ease as the tendon warms up, then return afterwards.
• A tender, sometimes thickened spot you can feel along the tendon.
• A grumbling ache after exercise or a long day, rather than a single moment of injury.

A sudden, severe pain with a "pop" and difficulty walking is different — that can signal an Achilles rupture, which is a separate, urgent problem and needs prompt assessment.

How is it diagnosed?

Like most tendon problems, Achilles tendinopathy is usually a clinical diagnosis — the history and a hands-on examination of the tendon are typically enough. Imaging such as ultrasound or MRI is reserved for unclear cases, for gauging severity, or when a tear is suspected.

How is Achilles tendinopathy treated?

The cornerstone is, perhaps surprisingly, loading the tendon in a controlled way rather than resting it completely. Conservative care is first-line, and progressive calf-strengthening exercises — particularly eccentric loading (slowly lowering the heel) — have the strongest evidence, with structured programmes achieving meaningful reductions in pain ¹. The broader plan usually includes:

• A progressive strengthening programme, ideally guided by a physiotherapist, continued for months.
• Activity modification — reducing aggravating load without going fully sedentary, then rebuilding gradually.
• Footwear and sometimes a small heel lift, which can ease an irritated tendon, especially in insertional cases.
• Patience — tendons remodel slowly, and improvement is measured in months.

One important caution: corticosteroid injections directly into or around the Achilles are generally avoided, because they are associated with a risk of tendon rupture. This is a tendon where the "quick fix" can backfire, which is why the unglamorous loading programme is the mainstay.

Recovery and preventing a recurrence

The same principles that treat Achilles tendinopathy keep it from returning:

• Build training up gradually and avoid sudden spikes in distance, speed, or hills.
• Keep your calves strong and flexible with ongoing maintenance exercises.
• Mind your footwear, replacing worn shoes before they break down.
• Warm up and treat early twinges as a signal to ease off, not push on.

Where do regenerative approaches fit?

For tendinopathy that refuses to settle despite a genuine loading programme, regenerative options are sometimes discussed. Honestly, the evidence is not yet strong: a 2021 systematic review and meta-analysis found mesenchymal stem cell therapy may improve pain and function in tendon disorders, but the authors emphasised that large randomised trials are still needed to confirm it ². So it remains an unproven, considered option for stubborn cases rather than a routine treatment — and at Cureon it is physician-led and offered only after assessment, with the limits explained plainly in our overview of regenerative medicine.

What we see at the clinic

The most common mistake we see is either total rest (which lets the tendon weaken) or pushing through the pain unchanged (which keeps it irritated). The sweet spot is controlled loading — enough to stimulate the tendon, not so much that it flares — and that takes guidance and time. We are also clear about what to avoid, including steroid injections straight into the tendon, and we keep expectations realistic about the months it usually takes.

Common questions

Why is it so stiff in the morning? Tendons tighten with rest, so the first movements of the day stretch an irritated Achilles before it has warmed up. Gentle early-morning calf movement often helps.

Can I keep running? Sometimes, at a reduced level, if the pain stays low and settles quickly — but this is best guided by a clinician or physiotherapist, because the right load is a balance, not a blanket rule.

How long does it take to recover? Usually months, not weeks, with a consistent loading programme. Tendons remodel slowly, and rushing tends to prolong things.

Is this the same as an Achilles rupture? No. A rupture is a sudden tear, often with a "pop" and trouble walking, and it is an urgent problem — tendinopathy is a gradual overuse condition.

Should I get an injection? Steroid injections into the Achilles are generally avoided because of the rupture risk. Any injectable option should be discussed carefully with a clinician.

Key takeaway

Achilles tendinopathy is a common overuse injury that responds best to the thing people least expect — progressive, controlled calf-strengthening — rather than rest or anti-inflammatory shortcuts. Give a proper loading programme real time, steer clear of steroid injections into the tendon, and treat regenerative options as unproven extras for stubborn cases, decided with a clinician.