Can I Get Compensation If the Accident Made an Old Injury Worse?

The first thing an insurance adjuster does after learning about your medical history is argue that your injuries pre-existed the crash. That argument has limits. A defendant who worsens a pre-existing condition is responsible for that worsening, and in many cases, for considerably more.

Pre-Existing Conditions and Car Accident Claims: What Big Auto Wants You to Know

A prior injury does not disqualify you from recovering compensation. What matters is not what condition you had before the accident, but what the accident did to that condition. Aggravating a pre-existing injury is its own compensable harm, and the law is clear on this point.

At Big Auto, we regularly fight insurers who use a client's medical history to deny or minimize legitimate claims. The legal framework protecting injured people with pre-existing conditions is well-established, and we know how to use it.

The Short Answer: Yes, You Can Still Recover

If a car accident worsened, accelerated, or aggravated a condition you already had, you have a valid claim for the harm the accident caused. You cannot recover for the pre-existing condition itself, but you can recover for everything the crash added to it.

This includes additional pain and suffering beyond what you experienced before the accident, increased medical treatment you would not have needed otherwise, lost income resulting from the worsening, and a diminished quality of life caused by the aggravation.

The fact that your spine was already degenerating, that you had a prior back surgery, or that you had been managing chronic pain does not give the at-fault driver a free pass.

The Eggshell Plaintiff Rule: Defendants Take Their Victims as They Find Them

The legal doctrine that protects injured people with pre-existing conditions is known as the eggshell plaintiff rule, sometimes called the thin skull rule. It holds that a defendant is responsible for the full extent of the harm they cause, even if that harm is far greater than it would have been for a healthier person.

The name comes from a straightforward idea: if you negligently strike someone whose skull is as fragile as an eggshell, you are responsible for the skull fracture that results, even though the same blow would not have injured a person with average bone density.

Applied to car accidents, the rule means that a driver who rear-ends someone whose spine was already compromised by degenerative disc disease is responsible for the herniated disc that results, even though the impact would not have herniated a healthy spine. The pre-existing vulnerability does not shift responsibility away from the at-fault driver.

What "Aggravation of a Pre-Existing Condition" Means as a Legal Claim

Aggravation and exacerbation are terms used to describe what happens when an accident worsens a pre-existing condition. They are distinct from causation claims, where the accident is alleged to have caused the condition in the first place.

An aggravation claim does not require proving the accident caused the underlying condition. It requires proving two things: that the accident caused the condition to worsen, and what the value of that worsening is.

This is often the central battleground in cases involving pre-existing conditions. The at-fault party's insurer will argue the condition would have worsened naturally over time anyway, that the accident contributed little to the current symptoms, or that all current treatment is attributable to the underlying condition rather than the crash.

Your attorney's job is to prove the distinction between the baseline and the crash-induced change.

How Common Pre-Existing Conditions Are Among Accident Victims

Pre-existing musculoskeletal conditions are not the exception. They are the norm. According to CDC data on pain prevalence among U.S. adults, nearly four in ten American adults reported back pain in the past three months. Tens of millions more live with arthritis, prior fractures, cervical or lumbar conditions, and a history of prior injuries.

The NHTSA's Crash Injury Research and Engineering Network specifically studies how occupant characteristics and premorbid conditions interact with crash biomechanics, recognizing that most crash victims do not arrive at the scene of an accident in perfect health.

An insurer who argues that your pre-existing condition defeats your claim is taking a position that the law does not support. The presence of a prior condition is common, expected, and legally irrelevant to whether you can recover for what the crash did to that condition.

How Insurance Companies Use Your Medical History Against You

When an insurer discovers a pre-existing condition, their approach is almost always the same: attribute as much as possible to the prior condition and as little as possible to the crash.

Common tactics include:

• Requesting years of prior medical records to find every documented complaint that resembles a current symptom
• Arguing that symptoms recorded after the accident are consistent with the natural progression of the prior condition
• Retaining defense medical experts who review your records without examining you and conclude the crash caused minimal new harm
• Disputing the credibility of your reported pain based on prior treatment notes
• Making low settlement offers framed around "the pre-existing condition issue"

None of these tactics eliminates your claim. They are negotiating positions that skilled attorneys counter with medical evidence, expert testimony, and documentation that isolates what the accident actually caused.

What Evidence Do You Need to Prove Aggravation

The strongest aggravation claims are built on a clear before-and-after comparison supported by objective medical evidence. What that requires:

• Medical records from before the accident establish the baseline condition
• Emergency and follow-up records from immediately after the accident documenting new symptoms or worsened findings
• Imaging comparisons, such as pre-accident and post-accident MRIs, showing a clear change in the condition
• Treating physician opinions specifically addressing whether and how the accident worsened the pre-existing condition
• Expert medical testimony was needed to explain the biomechanical mechanism of aggravation
• Documentation of treatment and costs that post-date the accident and were not part of the prior treatment history

A claim with clear before-and-after imaging and a treating physician prepared to testify about the causal connection is far more difficult to minimize than one built on subjective symptom reports alone.

Apportionment: What You Recover vs. What Was Already There

Aggravation claims involve apportionment. You cannot recover for the portion of your condition that pre-existed the accident. You can recover for the portion of the accident caused.

In practice, apportionment is rarely clean. Medical experts on both sides offer opinions on the percentage of current impairment attributable to the accident versus the underlying condition. The jury, or in settlement negotiations, the parties must evaluate that evidence and assign a value to the crash-related portion of the harm.

A plaintiff who had moderate back pain before an accident and now has severe, disabling pain has suffered a real and compensable loss for the difference. That difference is what the at-fault party owes.

Why Disclosing Your Pre-Existing Conditions Is the Right Strategy

Some accident victims are tempted to conceal prior injuries or medical history, fearing it will hurt their claim. This is a serious mistake.

Your medical records are discoverable in litigation. If an insurer or defense attorney finds a prior injury you denied having, your credibility on every other issue in the case is damaged. A claim that might have been settled amicably becomes one fought aggressively because the plaintiff's honesty is now in question.

The correct approach is transparency combined with strong legal framing. Disclose the prior condition, document the baseline, and build a case that clearly distinguishes between what existed before the accident and what the accident added. That story, told honestly and supported by evidence, is far more compelling than one that has gaps.

Big Auto Fights the Pre-Existing Condition Defense

Insurance companies treat pre-existing conditions as a default argument. At Big Auto, we treat it as a fight we are prepared to win.

Our car accident attorneys work with medical experts who can clearly separate pre-accident baseline from crash-caused aggravation, obtain and analyze pre-accident and post-accident imaging, and present the before-and-after comparison in a way that is clear to adjusters, mediators, and juries. We operate nationwide, with local co-counsel who know how courts in your jurisdiction evaluate aggravation claims.

If a prior injury was made worse by an accident you did not cause, do not let an insurer convince you that your history eliminates your claim. Contact Big Auto for a free case review and find out what you are owed for what the crash actually did to you.

Content reviewed by managing attorney, Nic Edgson. Nic has been an Arizona-licensed lawyer for more than a decade and focuses his law practice on helping people seriously injured in car accidents and truck accidents. He has represented thousands of clients and recovered more than $50 Million Dollars fighting for their injuries and medical bills. Throughout his legal career, Nic has helped those injured through some of the most difficult times in their lives.