Achilles Tendonitis Symptoms: Signs, Self-Tests and What to Do
The four symptoms that point to Achilles tendinopathy are morning stiffness at the back of the heel, pain that tracks how much you do, tenderness when you pinch the tendon, and a warm-up window where pain eases during activity then returns worse afterwards. Below are the symptoms in detail, three self-tests you can do right now, how to tell this apart from the other causes of heel pain, and the first steps of treatment. The Achilles rarely fails without warning, so reading the messages early is the difference between a few weeks of modified training and a frustrating year.
What Achilles tendonitis is
Achilles tendonitis, also spelled tendinitis and now more accurately called tendinopathy by clinicians, is an overload problem in the tendon connecting your calf muscles to your heel bone. The old model was pure inflammation, while current evidence describes a tendon whose structure is struggling to keep up with the load being placed on it. The NHS tendonitis page covers the basics.
It occurs in two locations, and the distinction changes the treatment:
- Mid-portion: pain 2 to 6 cm above the heel bone. The common version, especially in runners, and the one that responds best to loading.
- Insertional: pain right at the heel bone. Fussier about compression, so deep stretches and flat shoes often aggravate it.
The symptoms in detail
| Symptom | What it feels like | What it tells you |
|---|---|---|
| Morning stiffness | First steps out of bed feel stiff or sore, then ease within minutes | The signature sign, and the best day-to-day progress marker |
| Load-related pain | Fine walking, grumbles jogging, shouts on hills or sprints, often worse the day after | Confirms a capacity problem rather than an injury event |
| Local tenderness | Pinching the tendon reproduces the pain, often with a thickened, spindle-shaped area | Helps locate mid-portion versus insertional |
| The warm-up window | Pain eases mid-activity then returns worse afterwards | A shrinking window is the clearest warning that things are progressing |
| Stiffness after sitting | The first few steps after a long car journey or a desk stint | The same mechanism as morning stiffness |
| Weakness in push-off | Single-leg heel raises feel harder or fewer on the sore side | Common, and a target for treatment |
| Creaking or crepitus | A soft crackling when you move the ankle | Usually from the tendon sheath, uncomfortable rather than alarming |
Three self-tests you can do now
- The pinch test. Sit with your ankle relaxed and gently squeeze the tendon between finger and thumb, working from just above the heel bone upwards. Sharp local tenderness with thickening on one side compared with the other fits tendinopathy. Compare both sides, since tendons vary between people far more than they vary between your own two legs.
- Single-leg heel raise count. Standing on one leg with fingertips on a wall for balance, rise fully onto the toes and lower slowly, and count how many you manage before form breaks. Fewer reps or noticeably more pain on the affected side supports the diagnosis and gives you a number to retest in six weeks.
- Ten hops. Only if the heel raise test was manageable. Hop gently on the spot ten times. Pain that builds through the set, or pain the next morning, means the tendon's current capacity is below what you have been asking of it.
Track the first minute of your morning, scored out of ten. It is the single most useful measure for whether the plan is working.
What causes it
Tendinopathy is a capacity problem: load has outpaced what the tendon currently tolerates. The usual contributors, in line with the AAOS overview of Achilles tendinitis:
- A sudden jump in training, whether more distance, more hills, more speed work, or returning from a break at your old volume.
- Tight or weak calves, which push more strain through the tendon itself. The calf mobility guide covers assessing this.
- Footwear changes, particularly dropping into flatter or less supportive shoes than you are used to.
- Age-related tendon changes, since tendons become less elastic and less tolerant of sudden load from the mid-30s onwards.
- Some medications. Fluoroquinolone antibiotics are linked to tendon problems, and corticosteroids can be relevant too. Mention either to your GP if it applies.
- Health conditions including diabetes, inflammatory arthritis and raised cholesterol, all of which affect tendon health.
Tendonitis, rupture, or something else?
The urgent distinction first, because these need completely different responses:
| Feature | Tendinopathy | Rupture |
|---|---|---|
| Onset | Gradual, over days or weeks | Sudden, at a specific moment |
| What it feels like | Stiffness and ache that tracks load | A bang or pop, often described as being kicked in the calf |
| Push-off | Sore but working | Weak or absent, cannot rise onto the toes |
| Walking | Possible, if uncomfortable | Often still possible with a limp, which is the trap |
A clinician confirms a rupture in seconds with the calf-squeeze (Thompson) test: lying face down with the foot off the end of a bed, squeezing the calf normally makes the foot point, and in a complete rupture it does not move. That is a same-day assessment rather than a wait-and-see. There is a separate guide to Achilles rupture recovery.
Other causes of pain in the same area worth knowing about:
- Plantar fasciitis causes pain under the heel rather than behind it, sharpest with the first steps in the morning. See plantar fasciitis treatment.
- Retrocalcaneal bursitis produces swelling and tenderness in the soft spot between the tendon and the heel bone, often with shoe-related aggravation.
- Haglund's deformity is a bony prominence at the back of the heel that rubs against shoe counters.
- Calf strain is higher up in the muscle belly and comes on suddenly during activity.
- Sural nerve irritation gives burning, tingling or numbness along the outer side rather than a load-related ache.
What to do about it
The mainstay of treatment is progressive loading rather than rest. A reasonable starting plan while you arrange an assessment:
- Reduce the aggravating load rather than stopping. Cut hills, speed work and jumping first, since they load the tendon hardest. Keep walking and flat, easy activity.
- Start isometric holds if it is very painful. Rise onto both toes, shift most of your weight to the sore side, and hold for 30 to 45 seconds. Five holds, once or twice daily. Often reduces pain for a few hours.
- Progress to slow heel raises. Three seconds up, three seconds down, three sets of ten to fifteen, every other day. Start on two legs, progress to one, then add a rucksack for weight. For mid-portion problems, work off a step for extra range; for insertional problems, keep to flat ground and avoid dropping the heel below level.
- Use a small heel raise in your shoes for a few weeks if walking is painful, particularly with insertional problems. Both shoes, not just one.
- Be cautious with stretching. For insertional tendinopathy, aggressive calf stretching compresses the tendon against the heel bone and often makes symptoms worse.
Judge progress by morning stiffness rather than by how a single session felt. Pain up to about 4 out of 10 during exercise is acceptable if it settles within 24 hours and the next morning is no worse.
When to get it checked
- Same day: a sudden snap or pop, weak or absent push-off, or an inability to rise onto your toes.
- Soon: symptoms that persist beyond two to three weeks of sensible modification, pain at the heel bone that is not settling, or a tendon that is visibly swollen and getting worse.
- Promptly: pain that started shortly after taking a fluoroquinolone antibiotic, or symptoms in both Achilles tendons at once, which occasionally points to an underlying condition worth investigating.
Runners with confirmed mid-portion tendinopathy that has not responded to load management are sometimes offered shockwave therapy as a next step. Running's guide to shockwave therapy for Achilles tendinopathy in runners covers what that involves and what the evidence shows.
Three things I correct most often in clinic
- "It will settle if I rest completely." Symptoms settle while the tendon's capacity drops further, so it flares on return. Tendons recover through managed load.
- "Stretching harder will fix it." For insertional problems, aggressive stretching frequently makes things worse through compression. Strengthening comes first.
- "Pain means the damage is spreading." Tendon pain maps poorly onto structural change. Symptoms often improve markedly while a scan still looks unremarkable, which is why we treat the person rather than the picture.
FAQ: Achilles tendonitis symptoms
What are the first signs of Achilles tendonitis?
Mild morning stiffness at the back of the heel and a tendon that grumbles at the start of exercise but warms up. This stage responds fastest to load management, so do not wait for it to shout.
How do I know if it is tendonitis or something else?
Pain behind the heel that is tender to pinch and worse the morning after activity fits tendinopathy. Pain underneath the heel suggests plantar fasciitis, and burning or tingling suggests a nerve rather than the tendon.
Should I keep running with Achilles pain?
Often yes, in modified form. Keep pain during and after at 3 to 4 out of 10 or below, with no worsening morning stiffness the next day. Breach either rule and the load needs trimming.
How long does Achilles tendonitis take to heal?
Most people notice a clear change within 6 to 12 weeks of a structured loading programme, though tendons remodel slowly and full resolution often takes 3 to 6 months, longer for insertional or long-standing cases. Early, consistent, correctly dosed loading shortens that timeline.
Can Achilles tendonitis heal on its own?
Mild cases caught early sometimes settle once the aggravating load is reduced. Long-standing cases rarely resolve without a strengthening programme, since the capacity gap remains once the pain quietens.
Is walking good for Achilles tendonitis?
Usually yes, on flat ground and within comfort. Walking maintains tendon load without the impact of running, and total rest tends to make the return harder.
Should I use ice or heat?
Either, for comfort only. Ice can settle an angry tendon after activity, and heat often helps morning stiffness. Neither changes the underlying capacity problem.