Achilles Tendonitis vs. a Torn Achilles: What’s the Difference?
Jul 21, 2026
The two most common Achilles injuries are a torn Achilles tendon and Achilles tendonitis, an overuse condition where the tendon becomes inflamed and degrades over time. Both cause heel pain that radiates into the calf, swelling, and difficulty moving.
But they’re fundamentally different injuries that require different treatments.
Our team of sports medicine experts at South Texas Foot Surgeons, PA, in San Antonio and Kerrville, Texas, has the expertise to assess your Achilles properly, identify exactly what’s going on, and put together a treatment plan that gives you the best path to a full recovery.
In this month’s blog, we cover key differences between Achilles tendonitis and a torn Achilles, including what causes each, how they feel, how they’re diagnosed, and how they’re treated.
The Achilles tendon is the thick band of tissue connecting the calf muscles to the heel bone. While it’s the strongest tendon in the body, it’s also one of the most commonly injured.
Why? The Achilles tendon handles an enormous amount of force. Every step, sprint, and jump “runs through” this band of tissue. When it’s impaired or injured, you feel it immediately.
When you run, the load going through your Achilles tendon can be several times your body weight with each stride. It also has a relatively poor blood supply compared to muscle, which means it heals slowly and is more susceptible to gradual breakdown under repeated stress.
While athletes are at higher risk, Achilles injuries happen to recreational exercisers and people with desk jobs, too. A sudden increase in activity, tight calf muscles, worn-out footwear, and training on hard surfaces all contribute to Achilles problems, regardless of fitness level or age.
Achilles tendonitis develops gradually. Repeated stress on the tendon from running, jumping, or any activity that loads the calf repeatedly causes small tears within the tendon that accumulate faster than the tissue can repair itself. The result? The tendon becomes inflamed, thicker, and painful over time.
Achilles tendonitis pain typically starts as morning stiffness or a dull ache above the heel that eases with movement and returns after prolonged activity. The tendon often feels tender and thickened to the touch.
Most people push through this overuse injury for weeks before seeking help — which only serves to allow the damage to progress. Left untreated, Achilles tendonitis weakens the tendon structurally, and a weakened tendon is significantly more likely to rupture.
Treatment is conservative in most cases. It may include rest from aggravating activities, physical therapy (PT) focused on eccentric calf strengthening exercises, which are well supported by research for this condition, anti-inflammatory management, and, in some cases, shockwave therapy or platelet-rich plasma injections to stimulate healing.
A torn Achilles doesn’t build up over weeks; it happens in a single moment. Most people describe hearing or feeling a sharp pop at the back of the leg, often during a sprint, jump, or sudden change of direction. Many people initially think they’ve been struck by something because the sensation is that sudden.
A partial Achilles tear means some tendon fibers remain intact. A complete rupture means the tendon has torn through entirely, leaving the calf disconnected from the heel. A clinical test called the Thompson test, where the calf is squeezed while you lie face down, helps identify a complete rupture on examination. Imaging can confirm the diagnosis and show the extent of the damage.
Complete ruptures in active people are typically repaired surgically, where the torn ends are reattached. Research consistently shows that surgical repair produces a stronger tendon and a more reliable return to full activity than non-surgical management in active people.
Partial Achilles tears and ruptures in less active people can sometimes be managed with immobilization and rehabilitation, but that decision is made on an individual basis.
Achilles tendonitis and a torn Achilles tendon are two different injuries that happen to share some of the same symptoms. What sets them apart — and the treatment approach that each requires — is something only a proper assessment can determine.
If you’re dealing with Achilles pain, contact South Texas Foot Surgeons, PA, in San Antonio or Kerrville, Texas, to schedule an evaluation with our team today. We can assess your injury and devise a treatment plan that gives you the best chance of a full recovery.