Insulinoma is a very rare disease. It is a small tumour of pancreas which produces excessive insulin leading on to low blood glucose levels. It needs to be investigated in case some one has symptoms of hypoglycaemia which in fasting state are palpitation, feeling of marked hunger, sweating, irritability and rarely fits and unconsciousness. Usually when blood glucose is done during these symptoms it is < 50 mg/dl. First and foremost requirement is documentation of hypoglycaemia during these episodes. One gains weight over a time.
Once hypoglycaemia is documented, the next test is a prolonged fast (in a hospital setting) to confirm hypoglycemia with high levels of insulin levels followed by imaging of pancreas using either MRI or CT scan. Once diagnosed, treatment is surgery by an experienced surgeon.