Diabetic coma: Deep unconsciousness that results from uncontrolled diabetes associated with ketones in the bloodstream. The best treatment is prevention. Careful diet, medication, and insulin dosing, as needed, should prevent ketone buildup. Patients with diabetes and their family members should be aware of the early signs of ketone buildup, including weight loss, nausea, confusion, gasping for breath, a characteristically sweet, chemical odor, similar to that of acetone or alcohol (acetone breath), to the patient's breath, and sometimes sweat. Lethargy, confusion, and convulsions may precede diabetic coma. To prevent death, immediate emergency medical treatment is needed in a hospital setting for patients who show the early signs of diabetic coma.