How California’s Eggshell Plaintiff Rule Protects Your Injury Claim, Even With a Pre-Existing Condition
October 30, 2025- Categories: Personal Injury
In California, the person or party who caused your accident is responsible for the full extent of the harm you suffer, even if you had a pre-existing condition that made you more susceptible to injury.
This protection comes from a legal concept known as the “Eggshell Plaintiff Rule.” Simply put, a defendant must “take the plaintiff as they find them.” If a negligent driver causes a collision, they are liable for the resulting harm, whether they hit a professional athlete or someone with a previously injured back that has now been severely aggravated.
However, the at-fault party’s insurance company will closely examine your medical records. They will look for any opportunity to argue that your current pain is from an old injury, not the recent accident. Proving how the incident worsened your condition is where these cases are won or lost.
If you have a question about how a pre-existing injury might affect your accident claim, call us at (888) 407-2955.
What Is the “Eggshell Plaintiff Rule” in California?
The defense or insurance company might argue that your pain isn’t from the accident but from your old condition. They do this because their business model requires them to balance paying legitimate claims with maintaining profitability. By attributing your suffering to your past, they hope to pay you less or nothing at all.
The Eggshell Plaintiff Rule is the legal principle that directly counters this argument. The rule is officially reflected in California’s Civil Jury Instructions, which guide how a jury should interpret the law. Specifically, CACI No. 3927, “Aggravation of Preexisting Condition,” states that if a defendant’s wrongful conduct worsens a plaintiff’s prior condition, they must award damages to compensate for that effect.
This means two key things for you:
- You are not barred from recovery just because you were more fragile than the “average” person.
- The at-fault party is liable for all resulting damages, including the flare-up or worsening of a dormant or underlying condition.
This legal shield shifts the focus of the case. The question is no longer, “Were you already injured?” Instead, it becomes, “How did the defendant’s negligence make your condition worse?”
How Does a Pre-Existing Condition Actually Affect Your Injury Claim?
The Importance of Being Upfront
The single most damaging thing you might do in a case involving a pre-existing condition is to hide it.
During the legal process, both sides exchange information, and your past medical records will be requested. If you fail to disclose a previous injury or treatment and it’s discovered later, it severely damages your credibility in the eyes of an adjuster, a judge, or a jury. They might wonder what else you are not being truthful about.
When you work with an attorney, your role is to be completely transparent about your medical history. Our role is not to hide these facts but to frame them correctly. By understanding your complete medical picture, we build a strategy that proactively shows the clear “before and after” of your health, neutralizing the insurance company’s expected tactics.
The Insurance Company’s Investigation
It is standard procedure for an insurance company’s lawyers and adjusters to request years of your medical records. They are not doing this to understand your pain; they are searching for evidence to reduce their payout. They will look for any mention of similar symptoms, any previous complaints of pain in the same area of your body, or any prior diagnoses that could be blamed for your current condition.
Their goal is to build a narrative that you would have eventually needed the same medical treatments, experienced the same pain, or suffered the same limitations, even if the accident had never occurred. They want to create doubt about the cause of your injuries.
How We Counter Their Arguments
Our response to their investigation is methodical and evidence-based. We focus on two legal concepts:
- Causation: In California, we must prove that the accident was a “substantial factor” in causing your new or worsened injury. It does not have to be the only cause, but it must be a significant one. We use medical records, timelines, and expert opinions to draw a direct line from the defendant’s negligence to the harm you now suffer.
- Establishing a Baseline: The key is to paint a vivid picture of your life before the accident. We use your old medical records not as a liability, but as a tool to establish your baseline level of health.
- For example, perhaps your medical history shows that your degenerative disc disease was stable, managed with occasional physical therapy, and your pain was a 2 out of 10. After the accident, your new records show a disc herniation, a need for epidural injections, and a constant pain level of 8 out of 10. That contrast is the heart of your case.
How Do We Prove the Accident Worsened Your Condition?
Here’s how we work to demonstrate the connection between the accident and the aggravation of your pre-existing condition:
- Comprehensive Medical Records: We collect and analyze all relevant records from both before and after the incident. The goal is to create a detailed timeline. This timeline might show that before the accident, you saw your doctor once a year for a check-up on a chronic issue. After the accident, your records show emergency room visits, specialist consultations, diagnostic imaging like MRIs, and a new, intensive treatment plan.
- Consistent Medical Treatment: When you consistently attend appointments, go to physical therapy, and fill your prescriptions, you create an ongoing record of your injuries and your efforts to recover. This documentation shows an insurance company that your injuries are genuine and that you are taking them seriously.
- Medical Expert Testimony: We frequently work with respected medical experts who review your complete medical file. These experts provide a professional opinion, either in a written report or as testimony, explaining in clear medical terms how the specific forces of the accident (e.g., the impact of a car crash) would logically and foreseeably cause your underlying condition to flare up or worsen.
- Testimony from You, Friends, and Family: Statements from your spouse, friends, or coworkers are incredibly powerful. They describe the tangible changes in your life after the accident.
- For example, a spouse might testify, “She used to work in her garden for hours every weekend, but since the accident, she is unable to kneel for more than five minutes without being in terrible pain.”
Frequently Asked Questions About the Eggshell Plaintiff Rule
Do I have to tell the insurance company about my old injuries?
You must be truthful when asked direct questions, but you should not volunteer information to an insurance adjuster without guidance. Speak with an attorney before giving a recorded statement or signing any medical authorizations. How your medical history is presented matters. We help you provide the necessary information truthfully without giving the adjuster ammunition to use against you.
What if I was still treating my old injury when the new accident happened?
This makes a case more complex, but it does not make it impossible. In this situation, our focus is on proving how the new accident caused a significant setback, required a different or more intensive course of treatment, or resulted in a new and distinct type of pain beyond what you were already managing. The key is to clearly separate the “old” pain from the “new” pain caused by the accident.
Your Health History Isn’t a Liability; Let Us Show You Why
You did not ask for this accident, and you should not be punished for a health condition you were already managing. Your medical history does not give a negligent party a discount on the harm they caused. Under California law, your pre-existing condition is not a liability; it is a simple fact of your life that the at-fault party must accept.
The next step is simple. All you need to do is make one phone call to start the process of protecting your rights. Our firm offers a free initial consultation to discuss your case.
If you’re ready to discuss your situation, call Neale & Fhima: Accident, Injury, and Lemon Law Lawyers today at (888) 407-2955.
Attorney Aaron Fhima
Aaron Fhima is a trial attorney who has secured numerous settlements and verdicts against large corporations and some of the largest auto manufacturers in the world. Representing consumers and injury victims throughout the state of California, Aaron’s practice areas include personal injury, and lemon law litigation. Aaron has a long record of success taking on large defense firms; and he doesn’t hesitate to take cases to trial when necessary to enforce his clients’ rights. [ Attorney Bio ]
