Achilles Tendonitis is an inflammation of the tendon and sheath surrounding the Achilles tendon which produces pain behind the heel, ankle and lower calf when you walk or run. It is caused by stretching the tendon suddenly or repeatedly when you're not used to it. Usually, this happens when you train too fast or wear the wrong shoes.
Warning: If you ignore the symptoms and continue to run, you may cause your heel cord to rupture. This is an extremely serious injury and usually requires major surgery.
Self-Care can avoid potentially serious problems later. First STOP RUNNING until pain is gone, and use warm soaks. (If the injury is sudden, apply a cold pack right away.) Wear shoes with some heel. Do NOT wear tennis shoes or thongs. If the pain goes away, start doing the heel cord stretches.
Doctor's Care will probably treat the inflammation with oral medication or a steroid injection.
See a Foot Specialist to prescribe precision orthotics to help with Achilles Tendonitis.
Other treatments include stretching exercises, ultrasound treatments, shock wave therapy, rest, ice, compression, elevation, etc. See your Foot Specialist.