The occupation, 'Nurse Practitioners', include: Acute Care Nurse Practitioner, Adult Nurse Practitioner, Advanced Practice Nurse (APN), Advanced Practice Registered Nurse (APRN), Cardiology Nurse Practitioner, and other titles.Nurse Practitioners diagnose and treat acute, episodic, or chronic illness, independently or as part of a healthcare team. may focus on health promotion and disease prevention. may order, perform, or interpret diagnostic tests such as lab work and x rays. may prescribe medication. must be registered nurses who have specialized graduate education.