Gastroesophageal Reflux Disease (GERD): This is a common condition that can cause dysphagia, especially if the onset is somewhat acute. GERD can lead to esophageal inflammation and spasm, making swallowing difficult.

Esophagitis: Inflammation of the esophagus, often due to acid reflux or infection, which can cause dysphagia.
Eosinophilic Esophagitis: A chronic immune system disease in which a type of white blood cell, the eosinophil, builds up in the esophagus in response to an allergen or irritant, leading to difficulty swallowing.
Functional Dysphagia: A condition where there is difficulty swallowing without any obvious physical obstruction, often related to stress, anxiety, or other psychological factors.

Esophageal Cancer: Although rare in young adults, esophageal cancer can present with dysphagia and must be considered to avoid delayed diagnosis.
Achalasia: A rare disorder of the esophagus that makes swallowing difficult, caused by degeneration of the myenteric plexus, leading to failure of the lower esophageal sphincter to relax.
Foreign Body Obstruction: Especially if the patient has a history of eating disorders or if the onset was very sudden, an obstruction caused by a foreign body must be ruled out.

Scleroderma: A chronic autoimmune disease that can affect the esophagus, leading to dysphagia due to fibrosis and decreased motility.
Chagas Disease: Caused by the parasite Trypanosoma cruzi, this disease can lead to megaesophagus and dysphagia, though it is more common in certain geographic regions.
Esophageal Ring or Web: Abnormal formations of tissue that can cause intermittent dysphagia, often associated with iron deficiency anemia or other conditions.