Tendinitis and a tendon rupture are the most common Achilles tendon injuries.
Achilles tendinitis
Achilles tendinitis is a painful inflammatory condition. It’s common in runners but can affect anyone. When left untreated, Achilles tendinitis can become chronic and cause long-lasting mobility problems.
You may develop Achilles tendinitis if you increase the intensity or frequency of physical activity too quickly. You may also develop Achilles tendinitis if you participate in a sport that has quick starts and stops like basketball or soccer. Your risk of Achilles tendinitis increases if you have tight calf muscles, flatfeet, or a prior Achilles tendon injury.
Ruptured Achilles tendon
An Achilles tendon rupture is an acute injury that tears the tendon, causing immediate and severe pain. In most cases, an Achilles tendon rupture occurs during athletic activities. Your risk of rupturing your Achilles tendon is higher if you run uphill or on hard surfaces, or if you play a sport with quick starts and stops.