The basis of a valid medical malpractice case is that a doctor or other medical professional breached the duty of care owed to you or your loved one and that that breach directly caused harm. 

You might know that this occurred because of complications that arise after a medical procedure or care. The doctor or provider also might admit to making a mistake that has caused you harm. You may also discover that a provider did not provide informed consent and performed a procedure or treatment that you did not know about or approve of, which hurt you. Any of these scenarios could become grounds for a medical malpractice claim.