A prior back injury. An old knee surgery. A history of migraines. For many people injured in car accidents, a pre-existing condition becomes one of the first things the at-fault driver’s insurance company raises when evaluating the claim. Understanding how Illinois law addresses this situation matters significantly for anyone whose medical history might be used against them during the claims process.
The Eggshell Skull Rule
Illinois follows the principle known as the eggshell skull rule. The concept holds that a defendant must take the plaintiff as they find them. If an injured person has a pre-existing condition that causes them to suffer more serious harm than a healthy person might in the same accident, the defendant is still fully responsible for all harm actually caused by the crash.
In car accident claims, this means a driver who rear-ends someone with a pre-existing spinal condition is responsible for all resulting damages, including any aggravation of that prior condition, even if a person without that history might have walked away with only minor soreness. The at-fault driver does not receive a reduction in liability simply because the victim was more vulnerable than an average person. This principle is well-established in Illinois courts and applies directly to cases where prior injuries are at the center of the insurance dispute.
What Insurers Actually Argue
Knowing the legal rule doesn’t stop insurance adjusters from raising pre-existing conditions as a way to reduce what they offer. Common arguments include claiming that the injuries existed before the accident and are therefore not compensable, that ongoing treatment relates to a prior condition rather than the crash itself, or that the accident caused only a temporary aggravation of something that would have progressed regardless of the collision.
A Chicago car accident lawyer can work with treating physicians to document clearly what changed after the crash and distinguish new or aggravated conditions from the baseline state that existed before the accident occurred. That distinction, supported by medical records and provider opinions, is what counters the insurer’s narrative most effectively.
How to Build a Strong Claim Despite Prior Injuries
Protecting a claim when pre-existing conditions exist comes down to clear, consistent, and well-timed medical documentation. Several steps matter particularly in these cases:
- Establish your baseline condition with medical records from before the accident, so the starting point is documented rather than assumed
- Document any new symptoms, worsened symptoms, or functional limitations that appeared or increased after the crash
- Obtain a treating physician’s written assessment specifically addressing causation and the relationship between the crash and current symptoms
- Continue treatment consistently and follow all medical recommendations throughout recovery, because gaps in treatment are used by insurers to argue that claimed injuries aren’t as serious as presented
Why Consistent Medical Records Are the Core of the Case
Insurance companies discount claims where medical records are inconsistent, sparse, or don’t clearly connect the crash to the injuries claimed. The clearer and more consistent the record, the harder it is for an adjuster to argue that the prior condition accounts for everything. Medical providers who understand how to document injury causation in a litigation context make a real difference in how these claims resolve.
Disparti Law Group has represented Chicago accident victims whose claims were challenged on the basis of prior injuries or medical history. Building a documented and well-supported record of what changed after the crash is a central part of how these cases are prepared and presented.
If you have a prior injury history and were hurt in a car accident, speaking with a Chicago car accident lawyer can help you understand how to position your claim and respond effectively to the arguments the insurer is likely to raise from the start.
