Adult-onset non-insulinoma persistent hyperinsulinemic hypoglycemia, also known as NI-PHH, is a form of congenital isolated hyperinsulinism. This condition involves abnormal insulin production by the pancreatic beta cells, which leads to an excessive and uncontrolled release of insulin. The insulin secretion is not appropriate for the level of blood sugar, resulting in episodes of dangerously low blood sugar levels (hypoglycemia). In some cases, the abnormal insulin production can be diffuse throughout the pancreas or localized to a specific area. People with this condition experience repeated episodes of profound hypoglycemia that can be difficult to manage due to the condition’s resistance to typical treatments such as diazoxide.

A key symptom of this condition is recurrent episodes of profound hypoglycemia, which means that people experience very low blood sugar levels. These episodes are tied to the uncontrolled and excessive secretion of insulin. Information about additional symptoms is currently limited for this condition.

This condition is caused by an abnormal production of insulin by the beta cells in the pancreas. The hyperinsulinism is congenital and isolated, meaning it is present from birth and affects only the insulin-producing cells. Further genetic or environmental risk factors have not been detailed in the available information.