Achilles tendon pain can be caused by Achilles tendon injury, ankylosing spondylitis, tenosynovitis and so on. 1. Achilles tendon injury: Chronic strain injury to the Achilles tendon caused by wearing inappropriate shoes for a long time or jumping for a long time during sports may lead to Achilles tendon pain. 2. Ankylosing spondylitis: when suffering from ankylosing spondylitis, it may change the attachment points and involve the sacroiliac joints and spine, which will lead to the symptoms of Achilles tendon pain in the heel when it involves the root of the heel. 3. Tenosynovitis: When suffering from tenosynovitis, the affected area will secrete a lot of inflammatory factors, which may irritate the tendon sheath tissues, resulting in symptoms of heel Achilles tendon pain. As there are many causes of heel and Achilles tendon pain, it is recommended to go to the hospital for timely examination and diagnosis, and to carry out targeted treatment as soon as possible.