A Schatzki ring or Schatzki-Gary ring is a narrowing of the lower part of the esophagus

Esophagus

The esophagus is an organ in vertebrates which consists of a muscular tube through which food passes from the pharynx to the stomach. During swallowing, food passes from the mouth through the pharynx into the esophagus and travels via peristalsis to the stomach...

 that can cause difficulty swallowing. The narrowing is caused by a ring of mucosal tissue (which lines the esophagus) or muscular tissue. Patients with Schatzki rings can develop intermittent dysphagia

Dysphagia

Dysphagia is the medical term for the symptom of difficulty in swallowing. Although classified under "symptoms and signs" in ICD-10, the term is sometimes used as a condition in its own right. Sufferers are sometimes unaware of their dysphagia....

 (difficulty swallowing), or, more seriously, a completely blocked esophagus. The ring is named after the German-American physician Richard Schatzki

Richard Schatzki

Richard Schatzki was a German-American radiologist.Richard Schatzki trained in radiology in Berlin with Hans Heinrich Berg who was the leading diagnostic radiologist in Germany at that time. He immigrated to the USA in 1933 and subsequently worked as a radiologist in Boston...

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A Schatzki ring is a specific type of "esophageal ring", and Schatzki rings are further subdivided into A rings and B rings.