Medical malpractice is a form of negligence where an injury results from the failure of a medical professional or medical facility (doctor, nurse, medical technician, psychiatrist hospital, dentist, or other health care provider) to use adequate levels of care, skill, or diligence in the performance of his or her professional duties, thereby causing injury. In New York, a doctor's conduct is measured by the "reasonably prudent doctor" standard. The proper evaluation of this standard is sometimes complemented by the application of the "best judgment" doctrine. The law requires that a doctor use his or her best judgment and do what he or she thinks is best after a careful examination of the patient. A doctor's implied contract with the patient does not guarantee a good result, but rather promises by implication that the doctor will use the skill and learning he or she has acquired (at least that of the average physician) to exercise reasonable care and to exert good judgment in the effort to bring about a good result. Nestorowich v. Ricotta, 97 N.Y.2d 393 (2002). Of course, a doctor's best judgment must be exercised to improve the plaintiff's condition, not his or her own statistics or finances! In the case of a doctor who is a medical specialist, the standard of care is determined by the standard of good medical practice in that specialty within the community.
It is important to remember that the duty of a medical professional is not the duty to cure or even to guarantee a good outcome from treatment. Medical malpractice does not occur every time medical treatment is not successful. Rather, the duty is to provide good medical care according to accepted standards in the community, or, in the case of a specialist, accepted standards in that medical specialty. Medicine is not an exact science, and doctors are not required to be right every time they make a diagnosis. A misdiagnosis can be arrived at even when all proper tests are performed accurately or evaluated by a skilled doctor with the utmost care. A misdiagnosis constitutes malpractice, however, if the doctor fails to get a medical history, order the appropriate tests, or recognize observable symptoms of the illness.