The most common cause of gastroparesis is diabetes. People with diabetes have high blood glucose, also called blood sugar, which in turn causes chemical changes in nerves and damages the blood vessels that carry oxygen and nutrients to the nerves. Over time, high blood glucose can damage the vagus nerve.
Some other causes of gastroparesis are
• Surgery on the stomach or vagus nerve
• Viral infections
• Anorexia nervosa or bulimia
• Medications—anticholinergics and narcotics—that slow contractions in the intestine
• Gastroesophageal reflux disease
• Smooth muscle disorders, such as amyloidosis and scleroderma
• Nervous system diseases, including abdominal migraine and Parkinson’s disease
• Metabolic disorders, including hypothyroidism
Many people have what is called idiopathic gastroparesis, meaning the cause is unknown and cannot be found even after medical tests.