Many Californians live with pre-existing conditions such as old back injuries, arthritis, chronic migraines, prior surgeries, or conditions like degenerative disc disease. These health issues are incredibly common, especially among people who work physically demanding jobs or who have had previous accidents. If you’re worried about how a pre-existing condition could affect your future, you’re not alone. This is a concern for anyone who has a medical issue made worse by an accident.
So what happens when a new accident, such as a car crash, slip and fall, or truck collision, worsens a pre-existing condition? Does it hurt your personal injury case? Will the insurance company try to deny your claim if you have a pre-existing condition?
The short answer: insurance companies will almost always try.
But California law provides strong protections for victims whose prior conditions were aggravated or accelerated by someone else’s negligence.
Here’s what you need to know.
A Pre-Existing Condition Does NOT Bar a Personal Injury Claim
Insurance adjusters often say things like:
- “Your pain is from your old injury.”
- “You already had back problems, so this isn’t our responsibility.”
- “Your degeneration is normal for your age.”
These statements are designed to minimize your claim.
But they misrepresent the law.
Under California personal injury principles, you can recover damages if an accident worsens a condition you already had. The fact that you weren’t in perfect health does not eliminate the at-fault party’s responsibility.
In fact, California follows one of the strongest consumer protections for injured people: the Eggshell Plaintiff Rule.
Understanding California’s Eggshell Plaintiff Rule
The “Eggshell Plaintiff Doctrine,” recognized under California law, states:
A negligent party must take the victim as they find them, even if the victim is more susceptible to injury due to a pre-existing condition.
In other words:
- If your back or neck was already vulnerable
- And the accident caused more severe injuries than it would for an average person
- The at-fault party is still fully responsible for those injuries
You do not need to prove you were pain-free before the crash.
You do not need to prove your body reacted “normally.”
You only need to show the accident made things worse.
Aggravation vs. Exacerbation: Why It Matters with a Pre-Existing Condition
Doctors and attorneys often use two terms:
Aggravation
A long-term or permanent worsening of a pre-existing injury.
Exacerbation
A temporary flare-up of symptoms, lasting days, weeks, or months.
Both are compensable under California law.
For example:
- If you had a manageable neck injury from years ago and a crash makes it chronic again — that is compensable.
- If arthritis was mild but the accident accelerated degeneration — that is compensable.
- If an old surgical site becomes painful again — that is compensable.
You are entitled to damages for the difference between your condition before the accident and after the accident.
Common Pre-Existing Conditions Affected by a New Accident
Some conditions are especially vulnerable to worsening after a new injury:
- Degenerative disc disease
- Prior back or neck injuries
- Arthritis
- Migraines
- Herniated discs
- Previous fractures or torn ligaments
- Old concussions or head injuries
- Fibromyalgia
- Chronic pain syndromes
Even if your symptoms were mild—or barely noticeable—before the accident, a collision can reactivate or accelerate them.
Why Insurance Companies Try to Use Your Medical History Against You
Insurance companies in California routinely obtain medical records and search for any way to blame injuries on the victim’s past instead of the defendant’s negligence.
They often argue:
- “These MRI results look old.”
- “These symptoms were documented years ago.”
- “Your degeneration is typical for someone your age.”
This tactic is extremely common, especially in spine injury cases.
But courts recognize that degenerative changes are widespread.
A 40-year-old with “degenerative disc disease” is no different from a 40-year-old with wrinkles: it is a normal part of aging.
- Attorneys frequently work with medical experts who explain:
You may have had degeneration before, - But you didn’t have today’s level of pain, limitation, or dysfunction until the accident.
That difference is what the law compensates.
How to Strengthen Your Case When You Have a Pre-Existing Condition
Insurance companies attack cases involving pre-existing injuries more aggressively, but there are several steps you can take to protect yourself.
1. Seek medical care immediately—and be honest about your history
One of the biggest mistakes victims make is hiding their prior injury out of fear it will hurt the case.
It won’t. Hiding it will.
Doctors need to know your full history to properly document:
- What symptoms existed before
- What symptoms changed after
This comparison becomes powerful evidence later.
2. Tell your doctor exactly how the accident affected your condition
Make clear distinctions, such as:
- “My back pain was a 2/10 before the crash. Now it’s an 8/10.”
- “I used to get headaches once a month. Now I have them daily.”
- “I could lift groceries without issue before. Now I can’t.”
The more specific you are, the easier it is to prove aggravation.
3. Get updated imaging if recommended
MRIs, CT scans, and X-rays can often show:
- New swelling
- Fresh herniations
- Nerve compression
- Soft-tissue inflammation
- Worsening degeneration
Comparing new scans to older ones is one of the strongest forms of evidence in aggravation cases.
4. Follow through with your treatment plan
California insurers rely heavily on arguments like “gaps in treatment” or “treatment non-compliance.”
If your doctor recommends:
- Physical therapy
- Pain management
- Injections
- Surgery
- Chiropractic care
Make every effort to follow through so the insurer cannot claim your symptoms “must not be that serious.”
5. Keep pain journals and daily limitations records
Document:
- What activities you can no longer do
- How often pain occurs
- How your symptoms impact work, sleep, mobility, or family life
This creates a clear before-and-after picture.
6. Work closely with your attorney for help with pre-existing condition concerns
Your attorney can:
- Request the right medical records
- Highlight evidence showing aggravation
- Use experts to explain how the accident worsened your condition
- Fight insurer attempts to minimize your injuries
Personal injury cases involving prior conditions require careful handling, but they are extremely winnable with the right documentation.
What Damages Can You Recover in California with a Pre-Existing Condition?
Even with a pre-existing condition, victims are entitled to compensation for:
- All medical bills related to the worsening injury
- Future medical care if the accident created long-term damage
- Lost income and reduced earning capacity
- Pain and suffering
- Loss of enjoyment of life
- Emotional distress
If the aggravation creates a permanent disability, the settlement value may be significant.
Frequently Asked Questions
Will my settlement be smaller because I had a previous injury?
Not necessarily. If the accident made your condition significantly worse, your case may be worth more than someone who had no prior issues.
Do I have to share my entire medical history?
Typically, only records related to the injured area are required. Your attorney can prevent overly broad requests.
What if I was already seeing a chiropractor or doctor?
That actually helps—it establishes a baseline of symptoms before the accident.
What if I didn’t have symptoms before but had degeneration on imaging?
California law makes this clear: you can recover for the activation of a previously asymptomatic condition.
Can I still win my case if my injuries were mild before?
Yes. The key question is whether the accident caused new pain, new limitations, or a new need for treatment.
The Bottom Line for Pre-Existing Injury Victims
Having a pre-existing condition does not weaken your case in California personal injury law. In many situations, the accident victim with a prior condition has an even stronger claim because the crash triggered far greater harm.
If an accident worsened your old injury—or caused a flare-up of a condition you’d been managing—you have the right to pursue full compensation.
The important thing is to document everything, follow treatment recommendations, and work with an attorney who understands how to prove aggravation and fight back against insurance company tactics.
