How achalasia can cause breathing difficulties? please suggest exercises that'll help the food to go down to stomach if someone is having achalasia.

Esophageal achalasia: is the failure of the lower esophageal sphincter muscle to relax, resulting in retention of food/fluid in the esophagus, and regurgitation. Primary achalasia, the most common form, has no known cause. Unfortunately, the smooth muscle is not under voluntary control, so exercise won't help. Treatment can include lifestyle changes, medication, dilatation, or surgery. You need to talk to your doc.