The exact causes of achalasia cardia are still unclear. Achalasia cardia in an individual mainly occurs due to abnormal function of the lower esophageal sphincter due to improper relaxation and high resting pressure of the LES. Achalasia cardia is known to affect both muscles and the nerves which weaken and degenerate as the disease progresses. Various theories have been postulated in order to correlate the pathophysiology of achalasia cardia with the etiology. Some of these include:
- Genetic: Achalasia cardia is known to run in families and have a genetic predisposition.
- Abnormal Immune system: Certain auto immune responses in our body are known to cause considerable damage to the esophagus thereby weakening the muscles of the sphincter. This theory is more evident as individuals with other auto immune disorders are more prone to be at risk of achalasia cardia. This is one of the major causes of Achlasia Cardia.
- Nerve disturbances: Degeneration of certain nerves like vagus nerve and Aurebach's myentric plexus can lead to dilatation of the lower esophageal sphincter causing achalasia cardia.
- Idiopathic: Most cases of achalasia cardia have no underlying cause of its own.