The Impact of Pre Existing Conditions on Your Injury Claim

The Eggshell Plaintiff Rule Protects You

One of the oldest and most well-established principles in personal injury law is the eggshell plaintiff rule (also called the eggshell skull rule or thin skull rule). Under this doctrine, a defendant takes the plaintiff as the defendant finds them. If you had a pre-existing condition that made you more vulnerable to injury, the defendant is still fully responsible for the harm caused by the accident.

Texas courts have consistently applied this rule. In *Coates v. Whittington*, 758 S.W.2d 749 (Tex. 1988), the Texas Supreme Court held that a tortfeasor whose negligent act aggravates a pre-existing condition is liable for the entire damage resulting from the aggravation, even if the plaintiff would not have suffered the same degree of injury had they been in perfect health.

This rule exists because the law does not allow a negligent person to escape liability simply because their victim happened to be more vulnerable than average. A drunk driver who rear-ends a person with a prior back surgery is just as responsible for the resulting harm as if the victim had a perfectly healthy spine.

What Counts as a Pre-Existing Condition

A pre-existing condition is any medical condition that existed before the accident. Common examples include degenerative disc disease, prior herniated discs, osteoarthritis, prior surgeries, fibromyalgia, chronic pain conditions, prior traumatic brain injuries, mental health conditions such as depression or anxiety, and diabetes or other systemic conditions that affect healing.

Having a pre-existing condition does not mean your injuries are not real. It does not mean the accident did not make things worse. And it certainly does not mean you are not entitled to compensation. It simply means your case requires more careful medical documentation and legal strategy.

How Insurance Companies Use Pre-Existing Conditions Against You

Despite the eggshell plaintiff rule, insurance companies aggressively exploit pre-existing conditions. Their strategies are predictable.

They will request your entire medical history. The adjuster will ask you to sign a broad medical authorization that allows them to obtain records going back years or even decades. Their goal is to find any prior treatment for the same body part or condition and argue that your current symptoms are simply a continuation of your prior problems.

They will hire defense medical examiners. The insurance company will send you to a doctor of their choosing for an "independent medical examination" (IME). In practice, these examinations are anything but independent. The doctor is paid by the insurance company and frequently concludes that the plaintiff's current symptoms are attributable to the pre-existing condition rather than the accident.

They will argue you were already in pain. Even if the accident clearly worsened your condition, the adjuster will point to any prior complaints of pain in your medical records and argue that the accident did not cause any new injury.

They will cherry-pick your medical records. The adjuster will highlight every reference to prior symptoms while ignoring the portions of your records that show you were functioning well before the accident and significantly worse afterward.

How to Defeat the Pre-Existing Condition Defense

Winning a case with a pre-existing condition requires a combination of strong medical evidence and effective legal strategy.

Establish Your Baseline
The most important thing you can do is establish what your life was like before the accident. Your medical records from the period before the crash should show your level of function, your activity level, and whether you were actively treating for the pre-existing condition. If you had a bad back but were working full time, exercising regularly, and not taking pain medication, that baseline destroys the insurance company's argument that you were already disabled.

Get Your Doctor to Explain the Difference
Your treating physician is the most important witness in a pre-existing condition case. The doctor needs to explain, in clear terms, the difference between your condition before the accident and after. If your degenerative disc disease was stable and asymptomatic before the crash but became severely symptomatic afterward, the doctor's testimony connecting the change to the accident is critical.
Medical imaging can be especially powerful. If you had an MRI before the accident showing mild degeneration and an MRI after the accident showing a new herniation at the same level, the before-and-after comparison speaks for itself.

Use the Aggravation Instruction
Texas Pattern Jury Charge 15.4 provides an instruction specifically for cases involving pre-existing conditions. It tells the jury that if the defendant's negligence aggravated a pre-existing condition, the defendant is liable for the additional damages caused by the aggravation. Your attorney should ensure this instruction is included in the jury charge so the jury understands they are not being asked to ignore the pre-existing condition but rather to assess how much worse the accident made it.

Present Lay Witness Testimony
Family members, friends, coworkers, and neighbors who knew you before and after the accident can provide powerful testimony about the change in your daily life. A spouse who can testify that you used to play with your children every evening but now cannot get off the couch is more persuasive than any medical record.

The Lighting Up Doctrine

Texas recognizes what is sometimes called the "lighting up" doctrine. This principle holds that if a pre-existing condition was dormant (not causing symptoms) before the accident, and the accident "lit up" or activated the condition, the defendant is liable for all of the resulting symptoms.

For example, if you had degenerative disc disease that was not causing any pain, and a rear-end collision caused that previously silent condition to become painful and debilitating, the defendant is responsible for the full extent of your symptoms. The fact that you had degeneration on imaging before the accident does not matter if the degeneration was not causing problems.

Do Not Hide Your Medical History

One of the worst things you can do is hide your pre-existing condition from your attorney or your doctors. The insurance company will find it. Defense attorneys have access to pharmacy databases, prior claims databases, and your complete medical records. If they discover a pre-existing condition that you failed to disclose, they will use it to attack your credibility in front of the jury.

Honesty is always the best strategy. Tell your attorney about every prior injury, surgery, or medical condition. Your attorney can then build a case that addresses the pre-existing condition head on rather than being ambushed by it at trial.

Contact Medina & Medina for a Free Consultation

If you have been injured in an accident and you are worried that a pre-existing condition will hurt your case, call Medina & Medina at (512) 883-0012 for a free consultation. We have extensive experience handling cases involving pre-existing conditions and know how to defeat the insurance company's arguments. You pay nothing unless we win.