Gastroesophageal Reflux Disease (GERD): This condition is characterized by the backflow of stomach acid into the esophagus, leading to symptoms such as heartburn and difficulty swallowing. It's a common condition that can cause dysphagia due to esophageal irritation and spasm.

Esophageal Stricture: Narrowing of the esophagus due to chronic inflammation or scarring, often from GERD, can cause progressive difficulty swallowing.
Esophagitis: Inflammation of the esophagus, which can be caused by infection, allergies, or chemical injury, leading to dysphagia.
Achalasia: A motility disorder of the esophagus characterized by the inability of food to pass through the esophagus and into the stomach, causing difficulty swallowing.
Stroke or Neurological Disorders: Conditions affecting the brain or nerves controlling swallowing can lead to dysphagia.

Esophageal Cancer: Although less common, esophageal cancer can cause progressive difficulty swallowing and is critical to diagnose early for treatment.
Foreign Body Obstruction: Especially in children, but also in adults, an object lodged in the esophagus can cause sudden onset of dysphagia.
Pulmonary Embolism (if associated with dysphagia): Though rare, in some cases, a pulmonary embolism can cause sudden difficulty swallowing, among other symptoms.

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.
Scleroderma: A chronic disease characterized by deposition of collagen, replacing normal tissue, which can affect the esophagus and cause dysphagia.
Chagas Disease: Caused by a parasite, this disease can lead to achalasia and difficulty swallowing in its chronic phase, more commonly seen in certain geographic regions.
Zenker's Diverticulum: A condition where a pouch forms in the pharynx, which can trap food and cause difficulty swallowing.