Proving a medical malpractice claim can be incredibly complex, and requires the following four elements.
A doctor-patient relationship existed. Relatively easy to demonstrate with medical records, as it is proof that you hired the medical provider, and they agreed to treat you. Unless it was a consulting physician who did not directly treat you.
Negligence occurred from the doctor. For negligence to occur, requires establishing the appropriate “medical standard of care,” and proving there was a breach of that standard of care (medical negligence). In simpler terms, you must establish what diagnosis, course of treatment, or procedure was medically appropriate considering the circumstances, and exactly how the healthcare provider fell short in your treatment. Doing so, will require testimony from a medical expert. (A mistake by the doctor or simply being unhappy with the care you were given, does not mean medical negligence occurred.)
The negligence caused the injury. This can sometimes be difficult to prove, as the medical provider may take the stance that the original disease or injury that brought you in to be treated caused the harm you experienced. You must be able to demonstrate that it is “more likely than not” that the injury was caused directly by the doctor’s incompetent decision(s) or treatment. Once again, you will need to present a medical expert who will testify to this effect.
The injury caused specific damages. The case may indicate that the doctor performed below the standard of care, but you must also have suffered damages. Those may include physical pain, mental anguish, medical bills in addition to those for the original illness or injury, lost income and/or lost earning capacity.
Experienced lawyers will take the lead when it comes to formulating the best strategy to prove liability in your medical malpractice lawsuit. A large part of that strategy is going to consist of picking the right medical experts or witnesses in the same field of medicine as the defendant, to establish the medical standard of care that applied in your case and how it was deviated from.