Our friends at Warner & Fitzmartin Personal Injury Lawyers discuss how if you had a bad back, a healed fracture, or an old shoulder injury before your accident, you might assume it disqualifies you from filing a claim. It doesn’t. A personal injury lawyer can help you understand how a pre existing condition may affect your claim and how insurers may evaluate your injuries. But here’s the thing: pre-existing conditions do complicate the process, and understanding how insurers handle them can save you a lot of frustration down the road. 

The “Eggshell Plaintiff” Rule

Most legal systems recognize something called the eggshell plaintiff rule. The idea is simple: a person who causes an injury takes the victim as they find them, not as some hypothetical healthy version of that person. If a healthy individual would’ve walked away from a crash with a bruise but you ended up with a herniated disc because of a pre-existing spinal issue, the at-fault party is still generally responsible for the full extent of what actually happened to you.

That doesn’t mean insurers will make this easy. The truth is, adjusters look for any excuse to argue that your current pain existed before the accident and had nothing to do with what just happened. It’s one of the most common defense strategies in the book, and it works often enough that insurers keep relying on it.

How insurers try to minimize these claims

Expect an insurance company to request your full medical history once they learn about a prior condition. They’re not being nosy for no reason. They’re looking for documentation that suggests your current symptoms are simply a continuation of an old problem rather than something the accident caused or made worse.

Common insurer tactics include:

• Requesting years of unrelated medical records, sometimes going back a decade or more.
• Hiring a medical expert to argue the injury is degenerative rather than traumatic.
• Pointing to gaps in prior treatment as evidence the old condition had already resolved.
• Comparing pre-accident imaging to post-accident imaging to argue nothing actually changed.
• Each of these tactics is designed to shift the narrative away from what the accident caused and toward what was supposedly already there.

Why documentation matters so much here

The strongest way to counter these arguments is clear, contemporaneous medical documentation. If you were managing a prior condition reasonably well and it suddenly worsened after an accident, that shift needs to be clearly noted by a treating provider as soon as possible. Vague notes, inconsistent descriptions, or delayed treatment all give the other side room to argue that causation simply doesn’t exist.

It also helps enormously to be upfront with your own medical providers about your history from the very first visit. Trying to hide or downplay a pre-existing condition almost always backfires once the records eventually surface, and it can damage your credibility with an insurer or a jury far more than the underlying condition itself ever would.

Aggravation vs. New injury

There’s an important legal distinction between an injury that was aggravated by an accident and one that was newly caused by it, and this distinction shapes how a claim gets valued. Aggravation claims are common and entirely valid, but they typically require some form of expert medical opinion clearly connecting the dots between your “before” condition and your “after” condition.

Without that expert connection, an insurer has an easier time arguing that whatever you’re experiencing now would have happened anyway, accident or not. A qualified attorney can help identify what kind of expert testimony or diagnostic evidence might be needed to draw that connection clearly, since this specific issue is often where these cases are ultimately won or lost.

What this means for your settlement

Pre-existing conditions don’t just affect whether a claim is accepted, they can also affect how it’s valued. A well-documented aggravation claim, supported by clear medical opinion, can still result in fair compensation for the portion of your suffering the accident is responsible for. What tends to get lost in translation is nuance: insurers prefer black-and-white arguments, while these cases usually live in a gray area that takes careful documentation to resolve fairly.

The Bottom Line

Having a pre-existing condition doesn’t erase your right to compensation. What it does is raise the bar on documentation and proof, and it means insurers will scrutinize your case more closely than they would a claim from someone with a clean prior medical history. Insurers know this is an area where claimants often give up too early or accept a lowball offer out of frustration, so don’t let a prior injury talk you out of pursuing a legitimate claim. Consider consulting with a qualified attorney who can help sort out what’s compensable and what isn’t before you agree to anything.