The Achilles tendon is one of the strongest and biggest tendons in the human body. Even though this is the case, it is also one of the tendons in the human body that is most often injured or ruptured. There are four injuries that are most common to the Achilles tendon: Achilles tendinitis/tendinosis, paratenonitis, retrocalcaneal bursitis and rupture. Achilles tendinitis is a condition in which the Achilles tendon is acutely inflamed due to excessive overuse while tendinosis refers to an overused tendon that develops microtears in a chronic setting. Multiple etiologies might be at play in these diseases. Diagnosis of all four previously mentioned diseases is mainly done clinically but can be aided by plain radiograph, ultrasound and MRI. Paratenonitis is a condition that can be seen in runners and is an inflammation of the sheath that surrounds the Achilles tendon. Treatment is mainly conservative and very rarely operative to remove adhesions. Retrocalcaneal bursitis is a condition in which the retrocalcaneal bursa gets inflamed which can cause it to hypertrophy and adhere to the Achilles tendon. This can lead to degeneration of the Achilles tendon. Treatment of this condition is mainly conservative but can also in rare cases be operative. Achilles tendon ruptures are divided into four types according to the Kuwada classification and are most often treated accordingly either conservatively or operatively. There is no clear consensus on the etiology of the ruptures but there are multiple theories such as a previous insult or a diminution of blood supply in an older age.