Medical malpractice is the failure of a medical professional to follow the accepted standards of practice of his or her profession, resulting in harm to the patient. Usually, proof of failure to comply with accepted standards of medical practice requires the testimony of someone with expertise in the area of medical practice. Some states have special evidentiary rules applicable to malpractice claims.
The standard of care is usually established by expert testimony on how similarly qualified practitioners would have managed the patient's care under the same or similar circumstances. At one time such standards were referred to as the "standard of care in the community" but, with the globalization of information and credentialing, standards are now often considered to be national and not just simply related to the community. There are, however, special circumstances, as when a community is physically isolated from the rest of a country, that national standards might not apply.
Many medical malpractices cases involve failure to diagnose, and therefore, a failure to treat a condition. It may be that the doctor should have ordered certain tests, or failed to interpret tests ordered properly. Often, someone other than the ordering doctor interprets the test and prepares a report, for which the doctor is responsible to read carefully. In order to claim damages, a plaintiff must show that the condition was worsened by a failure to obtain timely treatment caused by the lack of or incorrect information. Malpractice that results in death can give rise to two separate claims: a malpractice claim for personal loss and suffering prior to death, enforceable by the decedent's personal representative, and a wrongful death claim for monetary loss to the decedent's spouse and next of kin.
Defendants in a medical malpractice case often claim that the injury complained of wasn't caused by their actions/inactions, were the result of the actions/inactions of another, or were caused by a pre-existing condition of the plaintiff's. Contributory and comparative negligence laws vary by state.