Esophageal manometry is the gold standard method for diagnosing achalasia. This study reveals high lower esophageal sphincter (LES) pressure and insufficient relaxation during swallowing. Complementary methods such as esophagography (barium swallow) and endoscopy are also utilized in the diagnostic process. Esophagography typically shows a dilated upper esophagus and a characteristic "bird's beak" narrowing distally. Endoscopic examination reveals significant resistance at the lower esophageal sphincter; the esophagus appears narrowed distally, and sometimes secondary changes due to chronic stasis, such as fungal esophagitis, may be observed.