If a patient feels the Achilles tendon begin to hurt, it may not necessarily lead to a rupture. This is usually not the case in my experience. In fact, most of my patients who tore their Achilles did not have any symptoms beforehand. They were unlucky and probably had a small defect in the tendon. It is rare for Achilles tears to occur on both sides.
This fear that patients have around the health of the Achilles, typically when it begins to get sore, is not justified. However, we do not know if we are beginning to feel just the tip of the iceberg with a bigger problem brewing.