Written by A Chicago crash can still be compensable even if you had a pre-existing condition. The question insurers actually care about isn’t whether you had a prior injury. It’s what the collision changed.
Insurers routinely pull old medical records to discount claims involving prior conditions. Strong documentation, a clear before-and-after timeline, and a working knowledge of herniated disc and back injury claims, pain and suffering damages, and how compensation works in Illinois are what separate a claim insurers can pick apart from one they can’t.
For a broader overview of the compensation framework this article builds on, see Compensation Basics in Illinois Car Accident Claims.
The Eggshell Plaintiff Rule: Illinois’ Answer to “You Were Already Hurt”
Illinois follows what’s commonly called the eggshell plaintiff doctrine, a long-standing common-law principle recognized by Illinois courts holding that a defendant takes the plaintiff as they find them. If you were more vulnerable to injury than an average person because of an existing condition, the driver who caused your crash doesn’t get a discount on liability because of it.
In practice: if a healthy person would have walked away from your crash with a sore neck, but your existing degenerative disc disease turned that same impact into a herniation requiring surgery, the at-fault driver is responsible for the herniation and the surgery, not just the sore neck a healthier person would have had.
Hypothetical illustration. Suppose a driver has lived with manageable, occasional lower-back pain from an old injury for years. A rear-end collision on Lake Shore Drive at a moderate speed aggravates that old injury into daily pain, reduced mobility, and a need for injections that weren’t necessary before. Under the eggshell rule, the at-fault driver is responsible for the worsening, the new pain, the new treatment, the new limitations, even though the underlying condition predated the crash. This is a representative example of how the doctrine applies, not a description of an actual case or outcome.
What insurers cannot legally argue, once aggravation is documented:
- “Your back was already bad, so this isn’t our responsibility.”
- “You would have needed this treatment anyway.”
- “This injury wasn’t caused by the accident, just revealed by it.”
None of those positions defeat a well-documented aggravation claim. What they do is stall it until you either give up or produce the medical proof that shuts the argument down.
Why Insurance Adjusters Push Back Harder on These Claims
Insurance companies exist to limit payouts. A claim involving a pre-existing condition gives them a specific argument to work with: that your current symptoms are simply the natural progression of an old problem, not something the crash caused or worsened.
That argument only works if you let it. Three adjuster tactics show up often enough in these cases to name specifically.
The friendly opening. An adjuster who sounds sympathetic in the first call is not doing you a favor. The goal of that friendliness is to get you talking about your medical history in detail, informally, before you’ve had a chance to think through what you’re revealing. Anything you say in that conversation can resurface later as evidence that your condition predates the crash.
The recorded statement request. Adjusters frame this as routine. It isn’t. A recorded statement, phrased casually, can be replayed later with a very different interpretation attached, “the same issues before the accident,” “not related to the crash,” language you never actually intended.
Skip it, or route it through a lawyer first.
The fast, low offer. A quick settlement offer shortly after a crash is timed to land before you know the full extent of an aggravated condition. Once you accept it, that’s final, no reopening the claim if the injury turns out to be worse than it looked in week two.
Conditions That Commonly Get Worse After a Crash
Some conditions are aggravated by car accidents more often than others, simply because of where and how they sit in the body.
Arthritis and joint disease. The sudden mechanical force of a collision can inflame joints that were previously manageable with medication alone, sometimes pushing a case toward injections or surgery that wasn’t on the table before.
Old fractures and surgical hardware. Plates, screws, and healed fracture sites are not designed to absorb a second impact. A crash years after an orthopedic surgery can shift hardware or re-stress the original injury site.
Degenerative disc disease and prior spinal injury. This is the most common aggravation claim we see. A spine already compromised by disc degeneration has far less margin before a collision’s force translates into a herniation, nerve compression, or new radiculopathy.
Cardiac conditions. The adrenaline spike and physical shock of a crash is not trivial for someone with existing heart disease. Post-crash cardiac events, while less common than orthopedic aggravation, do occur and require documentation tying the crash to the cardiac complication.
Neurological conditions, prior concussions, migraines, vertigo, also tend to worsen disproportionately after even a moderate-speed impact, since the nervous system doesn’t have the same margin for a second insult that it had before the first one. Rear-end collisions and intersection crashes, the two most common Chicago crash types, account for a large share of these aggravation cases specifically because of the sudden deceleration forces involved.
Related reading: Common Car Accident Injuries in Chicago.
What You Can Recover for a Worsened Condition
Illinois law doesn’t cap recovery for aggravated conditions differently than it caps recovery for new ones. The categories are the same ones available in any personal injury claim, applied to the portion of harm the crash actually caused.
Medical costs tied to the aggravation, imaging, specialist visits, physical therapy, injections, and any future treatment or surgery the aggravation now requires, are recoverable, provided your treating physicians can connect them to the crash rather than to the condition’s natural progression. This includes future medical costs where a physician can credibly project ongoing treatment, not just bills already incurred.
Lost wages and reduced earning capacity follow the same logic: if the aggravation, not the original condition, is what’s keeping you out of work or off certain duties, that loss is compensable. For someone whose pre-existing condition was already limiting their work capacity before the crash, the calculation gets more specific, the claim covers the additional loss the aggravation caused on top of whatever limitation already existed, not the full pre-crash earning capacity as if the condition never existed at all.
Pain and suffering damages account for the increase in pain and functional limitation the crash caused, not the baseline discomfort you already had. Emotional distress and rehabilitation costs, occupational therapy, vocational retraining, counseling, round out what a well-documented aggravation claim typically covers.
One point that surprises a lot of people: medical bills paid by your own health insurance for the aggravation-related treatment don’t reduce what you can recover from the at-fault driver. Illinois follows the collateral source rule, meaning payments from your own insurance are generally not deducted from a personal injury award, the at-fault party doesn’t get credit for coverage you paid premiums for.
The Statute of Limitations Doesn’t Bend for Aggravation Claims
Under 735 ILCS 5/13-202, Illinois gives you two years from the date of the crash to file a personal injury lawsuit. That deadline applies exactly the same way to an aggravated pre-existing condition as it does to a brand-new injury, there’s no extension for the extra medical documentation these cases require.
That’s the practical problem: aggravation claims typically need more evidence than a straightforward injury claim. You’re not just proving an injury happened; you’re proving how much worse it got because of this specific crash, which usually means before-and-after imaging, a treating physician willing to draw that line explicitly, and sometimes independent medical expert testimony. Building that record inside a two-year window means starting early, not waiting to see how treatment goes.
If Illinois’ comparative negligence rule under 735 ILCS 5/2-1116 also applies to your case, meaning the other driver disputes some portion of fault, you’ll want to understand how that interacts with an aggravation claim. Recovery is barred only once your own share of fault exceeds 50%; below that, your damages are reduced by your percentage of fault, not eliminated.
There’s a second layer worth knowing about specifically in aggravation cases: insurers sometimes try to argue comparative fault based on the pre-existing condition itself, suggesting that because you were already vulnerable, you bear some responsibility for the extent of your own injury. That argument doesn’t hold up under Illinois law. Comparative negligence applies to fault for causing the crash, not to a plaintiff’s physical vulnerability once the crash has happened. The eggshell plaintiff rule and the comparative negligence statute operate on separate questions, and conflating them is a tactic, not a legal argument.
Independent Medical Examinations: What to Expect
In a contested aggravation claim, expect the insurer to request an independent medical examination (IME), a physical exam performed by a doctor the insurance company selects and pays for, not one who has been treating you. IMEs in aggravation cases tend to focus heavily on distinguishing pre-existing findings from new ones, and the resulting report often becomes the insurer’s primary basis for disputing causation.
An IME doctor is not your physician and has no treatment relationship with you. Their report serves the party that retained them. That doesn’t make every IME finding wrong, but it does mean an IME conclusion that minimizes the aggravation should be weighed against your own treating physicians’ longitudinal records, records built over multiple visits by someone who has actually managed your care before and after the crash, not a single 20-minute exam conducted for litigation purposes.
Building the Record an Insurer Can’t Argue With
Three things distinguish an aggravation claim that survives insurer pushback from one that gets picked apart.
First: pre-crash and post-crash medical records, side by side. Without a documented baseline, there’s nothing for a doctor to compare the aggravation against.
Second: a treating physician, not just an attorney, willing to state in writing that the crash worsened the condition specifically. Insurers discount attorney arguments. They can’t as easily discount a treating doctor’s clinical opinion. The steps you take in the first days after a crash, documented in What to Do After a Car Accident in Chicago, shape how strong that baseline record ends up being.
Third: consistency. Gaps in treatment, inconsistent symptom reporting, or skipped follow-up appointments give an adjuster exactly the ammunition they’re looking for, “if it were really this bad, why did you stop treatment for six weeks?”
None of this happens by accident. It happens because someone is tracking it from the start.
One more detail worth knowing before you sign anything: insurers will typically ask you to sign a medical records authorization. Read what it actually authorizes before signing. A broadly worded release can give an insurer access to years of unrelated medical history that has nothing to do with the condition at issue, which they can then mine for anything that arguably supports their “pre-existing” argument. A properly scoped authorization limits access to records relevant to the body part or condition actually in dispute.
Where a Lawyer Actually Changes the Outcome
Aggravation claims are where the gap between self-represented outcomes and represented outcomes tends to widen the most, for a specific reason: proving “this got worse because of the crash” is a medical-causation argument, not just a liability argument.
A lawyer handling this type of claim is typically doing four things simultaneously: keeping the recorded-statement conversation from happening on the insurer’s terms, coordinating with your treating physicians to get the aggravation documented in the medical record rather than just described after the fact, valuing the claim based on what the aggravation actually costs going forward rather than what a first offer implies, and tracking the two-year filing deadline against everything else that has to happen before it.
Most firms handling these cases, including ours, work on contingency, no fee unless the case results in a recovery.
See also: Why Hiring a Chicago Car Accident Lawyer Matters.
Frequently Asked Questions
Does a pre-existing condition reduce how much I can recover?
It reduces recovery for the portion of harm that existed before the crash. It does not reduce recovery for the portion the crash caused or worsened, that part is fully compensable under the eggshell plaintiff rule.
Can the insurance company get my full medical history?
Generally only the records relevant to the body part or condition at issue, and typically through a signed authorization your attorney can limit in scope, not a blanket release of your entire medical history.
What if my doctor won’t say the crash caused the worsening?
You may need a second opinion or an independent medical evaluation. Without a physician willing to connect the aggravation to the crash in writing, the claim is significantly harder to prove regardless of how it actually happened.
Does it matter how minor the crash looked?
No. Property damage severity and injury severity are only loosely correlated, especially for spinal and joint conditions, a low-speed impact can meaningfully aggravate an already-compromised area.
How long do aggravation claims typically take to resolve?
Longer than a standard injury claim, generally, because of the added medical documentation and sometimes expert testimony needed. Settling too early, before the full extent of the aggravation is clear, is one of the more common mistakes we see.
Will an independent medical examination hurt my claim?
Not automatically. An IME finding is one piece of evidence among several. Consistent treatment records from your own physicians, built up over time, typically carry more weight with a jury than a single insurer-arranged exam.
Can I still recover if I stopped treatment for a while due to cost or scheduling?
A gap doesn’t automatically defeat a claim, but it does give the insurer an argument to make. Explaining the gap clearly and getting back into treatment as soon as possible limits how much that argument can be used against you.
Do I need to disclose my pre-existing condition to the insurance company?
You’re generally required to answer truthfully if asked, but you’re not required to volunteer your full medical history unprompted, and doing so in an informal phone call rarely helps your claim. Let the documentation speak for itself through the proper channels rather than through casual conversation.
More Illinois Injury Guides
- Can I Be Reimbursed for Lost Wages After a Car Accident in Chicago?
- Chicago Highway Crash Claims: Liability, Evidence, and Compensation
- Hit-and-Run Car Accidents in Chicago: What Victims Need to Know (and Why These Crashes Are Rising)
- Chicago Car Accident Lawyer Resources and Guides
If a Chicago crash made an existing condition worse, call (312) 346-4262 for a free consultation before you talk to the insurance company about your medical history. The earlier that conversation happens, the more real options you generally have for protecting the full value of the claim.
