Getting hurt is bad enough. But when you already have a medical condition before the accident, things can get complicated fast. Insurance companies love to argue that your pain “was already there,” but California law sees it differently. You still have rights, and with the right evidence and legal help, you can recover full compensation for the aggravation of your injury.
Here’s how pre-existing injuries affect personal injury claims in California and how to protect yourself when insurers try to use your medical history against you.
What Counts as a Pre-Existing Injury?
A pre-existing injury is any health condition you had before the accident occurred. These can be minor or serious, including:
- Back problems or herniated discs
- Old fractures or joint injuries
- Arthritis
- Prior concussions or traumatic brain injuries
- Psychological conditions like PTSD or anxiety
- Previous surgeries or chronic pain issues
Having any of these conditions doesn’t mean you can’t file a claim. Under California personal injury law, what matters is whether you recovered from those prior injuries or if the accident aggravated your existing condition—and that’s where your case becomes powerful.
The Eggshell Plaintiff Rule: California’s Legal Stance
California follows what’s known as the “eggshell plaintiff” doctrine, meaning the at-fault party must take the victim as they find them. In simple terms, if a negligent driver injures someone who is more vulnerable because of a prior condition, that driver is still fully responsible for the additional harm caused.
For example, if you already had a bad knee and a car crash made it worse, the driver cannot avoid liability by saying your knee was “already bad.” As long as the accident intensified your pain or created new complications, they’re still responsible for those damages.
This principle is recognized throughout California courts and ensures fair protection for people who were already managing medical issues before the accident.
How Medical History Affects Your Claim
Insurance companies will look closely at your medical records to find ways to reduce your payout. They’ll try to argue your symptoms were unrelated to the crash or were part of your pre-existing condition.
Here’s how your medical history can influence your case:
- Claim Value: If part of your injury existed before, the compensation may only apply to the worsening caused by the accident.
- Burden of Proof: You must show medical evidence that the accident aggravated your condition, not merely that it existed.
- Credibility: Being honest about your medical history builds trust. Concealing old injuries can harm your claim far more than disclosing them.
What Evidence Helps Prove Case Impact
The key to winning a claim involving a pre-existing injury is proving you had fully recovered from a prior injury or that the recent injury caused aggravation—that the accident made your condition worse or reactivated a dormant problem.
Helpful forms of evidence include:
- Medical records before and after the accident
- Doctor’s notes explicitly linking new symptoms to the crash
- Expert testimony from medical professionals
- X-rays, MRIs, or scans showing new or worsened damage
- A treatment timeline that starts immediately after the incident
The closer your treatment begins to the accident date, the easier it is to show that the crash, not time or aging caused the aggravation.
As discussed in The Role of Evidence in Personal Injury Lawsuits, documentation and timing are everything.
Why Pre-Existing Injuries Are a Favorite Defense Tactic
Insurance adjusters and defense lawyers often use prior medical issues as a way to limit compensation.
Common strategies include arguing your pain existed long before the accident, claiming your treatment isn’t related to the crash or blaming symptoms on age or degenerative conditions.
Don’t let them twist the facts. A skilled California personal injury lawyer can use your medical records and expert statements to show exactly how the accident worsened your condition.
Should You Disclose a Pre-Existing Injury?
Yes. Always. Trying to hide a pre-existing condition can seriously backfire.
Insurance companies and courts have access to your medical history. If they find inconsistencies, they may argue you’re being dishonest, which can weaken your entire claim.
Instead, be transparent. Focus on showing how you fully recovered or that the accident aggravated your prior injury. That honesty actually strengthens your credibility and legal position.
Real-Life Example: Back Pain Made Worse by a Rear-End Crash
Imagine you already had mild lower back pain from long hours at work. You stretched regularly and occasionally took pain medication. Then one day, you’re rear-ended at a red light.
After the crash, the pain becomes constant. You can’t sit or stand for long, and now you need physical therapy and injections.
This is a textbook example of a pre-existing condition aggravated by an accident. With proper documentation, such as before-and-after MRI scans and detailed physician reports, a lawyer can clearly show the difference in your medical condition and pursue full compensation.
Can Pre-Existing Injuries Affect Settlement Amounts?
Yes—but not necessarily in a negative way. You can still receive compensation if your condition worsens because of the accident. The settlement amount will depend on how much the injury was aggravated and how clearly you can prove it.
You may recover:
- Compensation for new or increased medical costs
- Damages for added pain and suffering
- Lost wages if your aggravated injury affected your ability to work
For more insight on how damages are calculated, check out: What Affects Slip and Fall Settlements in California.
When to Contact a Lawyer
If you have a pre-existing condition, contact a California personal injury lawyer as soon as possible. Early legal guidance helps you:
- Gather the right medical documentation
- Communicate properly with doctors
- Avoid insurance traps or recorded statements that can hurt your case
- Build a clear, evidence-backed narrative showing how the accident worsened your condition
Bottom Line: Your Health History Doesn’t Cancel Your Claim
Having a pre-existing injury doesn’t disqualify you from filing a personal injury claim in California. The key is proving that the accident worsened your condition—and working with a legal team that knows how to make that argument stick.
Insurance companies may try to shift blame, but California law protects you. With the right attorney, you can still recover compensation that reflects the true impact of the accident on your health and livelihood.
Need help proving your injury claim?
At Court House Lawyers, we know how to handle tough cases, especially those involving pre-existing conditions. You don’t have to face insurance companies alone.
Book your free legal consultation today to discuss your situation and learn how we can help you recover what you deserve.
