The title "registered nurse" (R.N.) may be used by people who have completed an approved nursing education program and received a diploma, a two-year associate's degree or a four-year bachelor's degree. They must pass a national nursing exam, and be licensed by the state.

According to the U.S. Bureau of Labor Statistics (BLS), "In all [registered] nursing education programs, students take courses in nursing, anatomy, physiology, microbiology, chemistry, nutrition, psychology and other social and behavioral sciences, as well as in liberal arts. All programs also include supervised clinical experience in hospital departments such as pediatrics, psychiatry, maternity and surgery. A number of programs include clinical experience in extended and long-term care facilities, public health departments, home health agencies, or ambulatory (walk-in) clinics."

R.N. duties may include tasks such as taking medical histories, observing and documenting observations about patients, creating care plans, analyzing test results, giving treatments, and teaching patients how to take care of themselves at home between office visits. R.N.s may also supervise other caregivers such as licensed practical nurses and aides. The average pay for a registered nurse is about $64,700 per year. (All salary figures in this article come from the national Bureau of Labor Statistics.)

Registered nurses who want to get additional training and expand the scope of their responsibilities may study to become nurse practitioners (who may also be called "registered nurse practitioners" and "advanced practice nurses"). They must complete a master's degree or doctorate in nursing, be licensed, and also be nationally certified in a specialty area, such as adult, pediatric, or family care.

In Arizona, nurse practitioners (N.P.s) do not need to work under the direction of a doctor. They may diagnose and treat patients on their own within the scope of their education and certification; they can prescribe drugs. They are expected to refer patients to doctors when necessary and to consult with doctors if the patient's needs exceed the scope of their expertise. That said, it is not unusual for N.P.s to choose to work in practices run by doctors. Nurse practitioners make about $91,500 per year on average.

While there are major differences in the training of physician's assistants (P.A.s, discussed in last week's column) and nurse practitioners, both types of professionals have at least a master's degree and can perform many of the services that doctors would otherwise handle. Research typically shows that patients get equally good results with all three - and that patients indicate a slight preference for nurse practitioners, because they feel that communication with N.P.s is better. That is, they feel that N.P.s both listen more carefully and provide better explanations of their conditions, treatments and so forth.

Another type of nurse is a licensed practical nurse (L.P.N.). These nurses typically operate under the direction of registered nurses or doctors to provide nursing care directly to patients. They do not independently diagnose patients or create new treatment plans for patients whose conditions are changing. They may supervise other L.P.N.s or unlicensed staff members such as aides. To become an L.P.N. in Arizona, candidates must complete a year of training, which includes both classroom and direct patient care experience. Then they must pass a national exam and be licensed by the state in order to practice. They earn on average $40,400 per year.

Other healthcare workers with "nursing" in their titles include "certified nursing assistants" (C.N.A.s). What training do they receive? In Arizona, C.N.A.s must receive 120 hours of instruction. One school whose website appeared early in online search results advertises that its program "can be completed in as few as seven weeks." Often, people studying to become C.N.A.s are working as aides in settings such as assisted living or skilled nursing facilities.

After completing training, C.N.A. students must pass both written and manual (hands-on) state exams. What tasks do C.N.A.s handle? According to the Bureau of Labor Statistics, C.N.A.s "provide basic patient care under direction of nursing staff. (They) perform duties such as feed, bathe, dress, groom or move patients, or change linens. (They) may transfer or transport patients." On average nationally, they make about $25,600 per year.

Titles that sound similar may describe care providers with very different education, experience and responsibilities. Don't hesitate to ask questions for clarification.