ABSTRACT
Achalasia is a disorder characterized by insufficient relaxation of the lower esophageal sphincter and absent peristalsis. It is usually primary (idiopathic) achalasia, but it can also be secondary achalasia (pseudoachalasia). With a review of the literature, epidemiological data was gathered on achalasia in this paper, and followed up with presented etiopathogenetic mechanisms of achalasia. An optimal diagnostic algorithm along with the therapeutic possibilities in achalasia, from endoscopic to surgical methods of therapy, was analyzed. The most common causes of pseudoachalasia and the mechanisms of this disorder are reported. In patients with dysphagia and suspected achalasia, it is important to distinguish idiopathic achalasia from pseudoachalasia, since pseudoachalasia most often occurs due to tumor infiltrations of the lower esophageal sphincter. In this paper, the importance of a timely and accurate diagnosis of pseudoachalasia in relation to idiopathic achalasia was shown.