A simple explanation is: when a healthcare provider, such as a doctor, nurse, or surgeon, has carelessly or recklessly performed his or her job and caused the patient harm.
Medical negligence legally speaking: Doctors and other medical professionals are held to a very high standard of care by the medical community and our legal system. “Standard of care” means the degree of prudence and caution they are expected to abide by. Whereas average people are expected to do most jobs with a “reasonable degree of care,” doctors and nurses are expected to do their jobs more carefully and attentively.
According to the Missouri jury instruction, negligence of a healthcare provider is defined as, "the failure to use that degree of skill and learning ordinarily used under the same or similar circumstances by the members of defendant's profession." Missouri Jury Instruction §11.06. To prove a medical negligence case, attorneys have to demonstrate that the healthcare provider acted less carefully and prudently than his or her colleagues do and should act in similar situations.
If a doctor provides substandard care based on what someone in his or her position would be expected to give to a patient, then that doctor is considered negligent and can be held liable for medical malpractice.