Mistakes and errors happen in most spheres of human life and activity, including in medicine. A mistake can be as simple and benign as the collection of an extra and unnecessary urine sample. Or a mistake can cause serious but reversible harm, such as an overdose of insulin in a patient with diabetes, resulting in hypoglycemia, seizures, and coma. Or a mistake can result in serious and permanent damage for the patient, such as the failure to consider epiglottitis in an initial differential diagnosis, resulting in a chronic vegetative state for a seven-year-old boy. Or a mistake can be an error in judgment that leads to a patient's death.