A certified nursing assistant (CNA) is an entry-level health care professional who offers regular clinical care to patients while supervising licensed health care practitioners. They may provide dressing, bathing and eating assistance, take vital signs and report the needs of patients to nurses and physicians. To join this career, it is essential to complete a certificate program in nursing assistance which typically involves some clinical experience along with the coursework. In addition to the state certification, a competency test is required to obtain the CNA title.