Overview
An Achilles tendon rupture is a tear or complete loss of continuity of the Achilles tendon, the strong band of tissue that connects the calf muscles to the heel bone. It usually causes sudden, sharp pain and rapid weakness because the tendon can no longer transmit force from the calf to push the foot downward. When the tendon is partially torn, strength loss may be less dramatic, but function is still often affected. Because proper immobilization and rehabilitation timing matter, early evaluation is important even when surgery is not the initial plan.
Symptoms
People often feel a sudden "pop" or tearing sensation at the back of the ankle, followed by pain and swelling near the heel. Walking may become difficult, especially pushing off during steps, and the foot may feel weak as if it won't "work" properly. You may notice bruising along the heel or calf and trouble standing on tiptoes on the affected side. Pain may worsen with attempts to push the foot down or climb stairs, while rest may reduce discomfort.
Causes
Achilles tendon ruptures commonly occur from a sudden forceful push-off, such as during sprinting, jumping, or quick changes in direction. In many cases, the tendon has been weakened by degeneration or overuse, making it more vulnerable to a traumatic snap. Direct impact to the tendon can also contribute, but the typical mechanism is overload of a compromised tendon.
Risk Factors
Risk increases with age because tendon tissue becomes less resilient and recovery can be slower. Prior tendon problems, such as chronic Achilles tendinopathy or repeated calf tightness, can predispose the tendon to tearing. Certain medications, including some antibiotics (fluoroquinolones) and oral steroids, may increase susceptibility. Training errors such as sudden increases in running intensity, inadequate warm-up, and poor footwear or uneven surfaces also raise risk.
Prevention
Reduce risk by building speed and volume gradually rather than making abrupt jumps in training. Maintain calf flexibility and strength with consistent, progressive conditioning, and avoid "cold" sprinting without a proper warm-up. If you develop Achilles pain or stiffness, reduce load early and consider a clinician-guided plan before symptoms worsen. Using appropriate footwear and paying attention to running mechanics can also help limit tendon overload.
How the Diagnosis Is Evaluated
Clinicians start with a focused history about a sudden pop, immediate weakness, and difficulty push-off. A physical exam commonly includes checking calf squeeze strength and comparing ankle movement to the other side, including the Thompson (calf squeeze) test. Imaging may be used to confirm the rupture or determine whether it is partial, with ultrasound or MRI often selected if the exam is unclear. Not every patient needs advanced imaging if the exam strongly suggests rupture and management will not change.
Nonsurgical Treatment Options
Many patients can be treated without surgery using immobilization and a structured rehabilitation plan, especially when a brace or casting protocol can be followed. Treatment typically involves keeping the ankle plantar-flexed (toe-down position) using a walking boot or cast initially, often with heel lifts to reduce tension on the tendon. As healing progresses, physical therapy focuses on restoring range of motion and gradually rebuilding calf strength and function through controlled loading. Pain control may include activity modification and short-term use of NSAIDs if appropriate for your health history. Regenerative injections such as platelet-rich plasma (PRP) are sometimes discussed as an adjunct in selected cases, but they are not a standard replacement for immobilization and rehab, and results can vary.
When to Seek Medical Attention
Seek prompt medical attention if you experience a sudden pop at the back of the ankle, new inability to push off, or rapidly increasing swelling and bruising near the heel. Urgent evaluation is recommended if you cannot stand or bear weight, if there is major deformity, or if you suspect a complete rupture based on significant weakness. Get immediate care if you have fever, severe worsening pain despite rest, or any concerning neurologic symptoms such as progressive numbness or loss of function.
Frequently Asked Questions
Yes, many ruptures can heal with non-surgical immobilization followed by a carefully timed rehabilitation program, though outcomes depend on the type of tear and how consistently the plan is followed.
Recovery commonly takes months, with gradual return of walking, strength, and sport-specific activity as guided by symptoms and exam findings.
Physical exam tests for tendon function and comparison to the other side are key, and ultrasound or MRI may be used when the exam is unclear.
Stop activity immediately, avoid forcing push-off, protect the ankle in a supportive position, and arrange prompt evaluation.
Early on, you may need limited weight-bearing and assistive support, and your clinician will give guidance to protect healing while you remain safe.
Next Steps
If you suspect an Achilles tendon rupture, arrange a prompt in-person evaluation so the tear type and tendon function can be confirmed. Follow the clinician's guidance on immobilization and begin rehabilitation when appropriate to protect healing and restore strength. If you cannot bear weight or have marked weakness, seek urgent care.