Dysphagia is usually observed early in the evolution of the disease, and is caused by the inability of the LES to relax. As the esophagus becomes progressively dilated and accumulates large amounts of solid food, overflow regurgitation occurs. Due to a reclining position, regurgitation during the night can lead to aspiration pneumonia and pulmonary abscesses. Achalasia is insidious, as patients may not notice impairment of esophageal emptying for months to years. Inability to adequately swallow leads to weight loss in more than half of these patients.
Diagnosis requires the use of esophageal manometry, endoscopy, and radiography.
Manometry is the diagnostic test of choice when achalasia is suspected. Endoscopy must be performed in all patients to rule out more common causes of dysphagia such as Schatzki ring, benign strictures, or malignancy. A dilated esophagus with a tight LES is characteristic of achalasia. The esophagoscope can easily be passed through the LES into the stomach except in patients with malignant strictures. Air or fluid behind the heart is occasionally seen on plain chest X-rays.