Hello, Most common cause of tightness in Achilles tendon is Achilles tendinitis. Achilles tendinitis is an overuse injury of the Achilles tendon. Achilles tendinitis most commonly occurs in runners who have suddenly increased the intensity or duration of their runs. It s also common in middle-aged people who play sports, such as tennis or basketball, only on the weekends. Risk factors for developing Achilles tendinitis: Age: as age advances, more risk Gender: more risk in men Flat foot Obesity Running in worn out shoes High blood pressure Psoriasis Use of antibiotics called fluoroquinolones. Pain medication like ibuprofen, naproxen will help reduce pain. Physical therapy: Therapists often prescribe specific stretching and strengthening exercises to promote healing and strengthening of the Achilles tendon and its supporting structures. Eccentric strengthening is very useful. Orthotic devices like shoe or a wedge to slightly elevate your heel. Preventions are increase your activity level gradually. Choose your shoes carefully. Avoid activities that put excess stain on your tendon like hill running. Stretch daily and not just on weekends. Strengthening of calf muscles. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Pallavi M., Anesthesiologist