Gastroesophageal Reflux Disease (GERD): This is the most common cause of dysphagia in a non-smoking young adult. GERD can lead to esophageal inflammation and strictures, causing difficulty swallowing.

Eosinophilic Esophagitis: An allergic inflammatory condition that can cause dysphagia, especially in young adults. It's often associated with atopic diseases like asthma.
Functional Dysphagia: A condition where there's difficulty swallowing without any obvious physical obstruction. It can be related to stress, anxiety, or other psychological factors.
Esophageal Spasm: Abnormal muscle contractions of the esophagus can cause intermittent dysphagia.

Esophageal Cancer: Although rare in young adults, especially non-smokers, it's crucial not to miss this diagnosis due to its severe prognosis. Certain types, like adenocarcinoma, are increasing in incidence.
Achalasia: A rare motility disorder of the esophagus that can cause progressive dysphagia. Early diagnosis is essential for effective management.
Foreign Body Obstruction: Accidental ingestion of a foreign body can cause sudden onset of dysphagia and is a medical emergency.

Scleroderma: A systemic disease that can affect the esophagus, leading to dysphagia due to fibrosis and decreased motility.
Chagas Disease: Caused by Trypanosoma cruzi, it can lead to megaesophagus and dysphagia, though it's more common in endemic areas.
Esophageal Webs or Rings: Thin, membranous structures that can partially obstruct the esophagus, causing dysphagia. They are often congenital or associated with certain conditions like Plummer-Vinson syndrome.