A defendant (at-fault party) is only liable for compensating a plaintiff (victim) for the injuries directly caused by their negligence. As a result, pre-existing injuries often create a legal grey area since it can be challenging to differentiate a pre-existing injury from current injuries. Additionally, it can actually be a disadvantage if you were in treatment for a pre-existing condition before the accident. Suspicion may be raised about reimbursing medical care after the accident that you were already receiving before it. As a result, you must be able to provide medical evidence that the accident furthered or aggravated your injury, or you risk the insurer denying compensation for your medical care.
Keep in mind that pre-existing injuries or conditions do not disqualify you from recovering compensation. An attorney can ensure your claim is successful by helping you establish the difference in your injury severity before and after the accident, as well as how your life has been impacted.