Esophageal achalasia is a neurogenic motor abnormality with the loss of normal peristalsis and insufficient relaxation of the lower esophageal sphincter, leading to dysphagia and chest pain, with no response to proton pump inhibitor therapy.
Esophageal achalasia usually sets in between the second and the sixth decade of life. Onset is insidious and symptoms gradually become more severe.
Patients present with dysphagia  for both solids and liquids , which differentiates it from dysphagias that only involve solids and are characteristic of tumors of the gastroesophageal junction. Regurgitation of food and saliva is another trait of this disease. Affected individuals also describe nocturnal regurgitation that may lead to aspiration. Substernal chest pain associated with meals leads to progressively diminished amounts of ingested food and weight loss . Additional symptoms include heartburn  and nocturnal cough caused by acid reflux or retention of food in the esophagus .
The clinical examination in uncomplicated esophageal achalasia does not detect pathologic elements .
Tests which are valuable when trying to establish the diagnosis of esophageal achalasia: barium esophagogram, upper gastrointestinal endoscopy, and esophageal manometry.
Barium esophagogram establishes the morphology of the esophagus and the esophagogastric junction and evaluates the peristalsis. The esophagus can be dilated, angulated or tortuous and a narrow gastroesophageal junction with "bird neck" appearance has been described. Barium emptying is impaired and prolonged  .
Esophageal manometry shows the lack of normal peristalsis  with improper lower esophageal sphincter relaxation  leading to inadequate emptying in the absence of an obstruction. The esophagus may be atonic or non-contractile. Sphincter relaxation may be impaired completely, partially or not at all  . On the other hand, esophageal pressure may be increased in all esophageal areas.
Upper gastrointestinal endoscopy is used in cases where a mechanical obstruction cannot be excluded , especially since achalasia symptoms may overlap with those of an infiltrative neoplasm. When trying to enter the stomach, a pressure described as a “pop” may be felt by the endoscopist while passing through the gastroesophageal junction. Finding food or saliva above the gastroesophageal junction is pathognomonic for achalasia. Endoscopic ultrasound is especially useful if a neoplasm is suspected. Furthermore, the mucosal examination is important in differentiating achalasia from acid reflux disease, peptic strictures and candida infection . Endoscopy is especially useful in patients with systemic sclerosis, where manometry also shows abnormal peristalsis.
High-resolution manometry allows a more precise diagnosis of achalasia subtype. Chest X-ray may describe chronic pneumonia due to aspiration and a small or absent gastric air bubble. The trachea may be pushed anteriorly or may be bowed, due to compression by the dilated esophagus. Computer tomography is indicated if complications are suspected, as it identifies areas of mucosal thickening. Esophageal pH measurement is important in ruling out acid reflux disease .
Blood workup often shows no abnormal findings.