Achilles tendon pain can be due to Achilles tendonitis (inflammation) or tendonosis (degeneration). These conditions can be the result of increased strain over a long period of time, returning to activities after an extended period of inactivity, or a sudden increase in speed or distance of activity. Tightness of the calf muscles, and excessive rear-foot pronation ('ankles rolling in') can increase the likelihood of injury to the Achilles tendon.
People suffering from Achilles tendon pain can experience it during or after activity. Pain or stiffness may also be present in the morning. The pain is usually felt behind the heel and sometimes along the tendon up the leg.
Treatment can vary depending on the cause of the pain but can generally include: Icing, rest, correction of any over-pronation, footwear advice, and NSAIDs (Non-steroidal Anti-Inflammatory Drugs).