Currently there are no existing data to determine why some achalasia patients lose weight while others do not. The purpose of this study is to gather data from patients diagnosed with achalasia to determine if differences may be identified between those who lose weight and those who do not that would help us better understand the mechanism of weight loss in this population.

Patients either diagnosed with or being evaluated for achalasia and scheduled for standard clinic visits with the principal investigator as part of their routine care will be considered for participation in this study. Blood work, vital signs, and 24-hour dietary recall will be collected over a period of one year. These data will lay the foundation for future scientific endeavors to : a) assess requirements for dietary and/or nutritional supplements; b) formulate an achalasia diet; c) develop clinical practice standards; and d) design an intervention study.

Inclusion Criteria:

1. Subject is able to provide written informed consent to participate in the study before completing any study-related procedures
2. Subject is male or female aged 18-75 years, inclusive at time of consent.
3. Subject has a documented diagnosis of achalasia based on high resolution manometry and endoscopy report.
4. Subject has been or will be scheduled to undergo either EGD with pneumatic dilation or surgical myotomy as routine care for treatment of achalasia.
5. Subject is willing and has an understanding and ability to fully comply with study procedures and restrictions defined in this protocol.

Exclusion Criteria:

1. Subject has any condition or abnormality, current or past that, in the opinion of the principal investigator, would compromise the safety of the subject or interfere with or complicate the assessment of signs or symptoms of achalasia. Such conditions may include psychiatric problems; neurologic deficits or disease; developmental delay; lung transplant; or previous gastroesophageal surgery.
2. Subject has had previous pneumatic dilation of treatment of achalasia.
3. Subject has had botulinum toxin (botox) injection for treatment of achalasia.
4. Subject has a history or high risk of noncompliance with treatment or regular clinic visits.

Patients either diagnosed with or being evaluated for achalasia and scheduled for standard clinic visits with the principal investigator or a sub-investigator as part of their routine care.