An advanced practice nurse (APN) is a registered nurse (RN) who possesses at least a master's degree in nursing (MSN). According to Discover Nursing, there are four types of APNs: Nurse Practitioner (NP), Certified Nurse-Midwife (CNM), Clinical Nurse Specialist (CNS) and Certified Registered Nurse Anesthetist (CRNA). Through additional education, these nurses have acquired training that allows them to treat patients in areas beyond those provided to registered nurses.

Educating Patients

Nurse Practitioners prescribe medications, treat illnesses, obtain medical histories and administer physical exams, according to Nurse Practitioner Central. Unlike physicians, NPs focus on prevention and wellness. For instance, they provide their patients with information to allow them to make informed decisions about their health. NPs also administer immunizations and other preventative child care. Many NPs work in primary and acute care settings, including private practices, clinics, health departments, hospitals, home health care agencies and nursing homes.

Specialized Medicine

Clinical Nurse Specialists use their expertise in clinical practice, education, consultation and research. They care for the patient and the patient's families, and collaborate with other medical professionals to assess and develop a plan to make sure the patient receives the best care. In addition, as an educator, CNSs teach other staff members and can find their place in research. Many specialists opt to work in an area of interest such as diabetes, cardiology, respiratory, pediatrics or psychiatric-mental health, according to the North Carolina Center for Nursing.

CRNA Work

Keeping patients pain-free is the goal of a Certified Registered Nurse Anesthetist. CRNAs administer anesthesia for all medical procedures, including surgery and childbirth, in collaboration with surgeons, anesthesiologists, dentists, podiatrists and other health care professionals. CRNAs monitor the patient's bodily functions after the procedure to ensure safety and comfort. According to the American Association of Nurse Anesthetist, an individual must complete and pass a national certification exam administered by the Council on Certification of Nurse Anesthetists.

Nurse-Midwives and Women's Health

Certified Nurse-Midwives deliver comprehensive health care services to pregnant women, newborns and the families. Some of their duties include prenatal, labor and delivery, and postpartum care; gynecological exams and menopausal management. A majority of nurse midwives, according to the American College of Nurse-Midwives (ACN-M), work in private practice, as part of an obstetrics/gynecology practice or as entrepreneurs in birth centers or home birth practices. With the advent of sophisticated obstetrics wings, CN-Ws have found more job opportunities in hospitals. The ACN-M reports that CN-Ms are required to pass a national examination for certification administered by the ACN-M Council.

Adding Credentials

While a certification is required for all of the above-mentioned nurses, specialized credentials are available to APNs. The American Nurses Credentialing Center (ANCC) provides exams and certifications in several APN-level areas. For example, a nurse practitioner interested in acute care nurse practitioner certification, must complete the required education, field experience and credentials to sit for the exam. Upon passing the exam, the nurse practitioner can wear the credential. Some certification options are built into the APN's master's degree program, which allows candidates to transition into their future career goal a little easier.