Glossary
Pre-existing condition
A health problem you had before the crash. You generally cannot claim for the condition itself, but you can claim for the extent to which the crash made it worse.
General information, not legal advice. Talk to a licensed attorney in your state.
Quick answer
A pre-existing condition is a health problem you had before the crash. You generally cannot claim for the condition itself, but you can claim for the extent to which the crash made it worse.
In a car accident claim#
Insurers often look for earlier records, especially in back and neck claims. Age-related wear is common: by age 60, most people show signs of cervical spondylosis on x-ray, according to MedlinePlus. Finding such changes on a scan does not end a claim. California's jury instruction, for example, allows damages for the effect of the crash on a physical or emotional condition that it made worse, but not for the condition the person already had.
The dispute then turns on Causation. The link between someone's careless act and your injury. You must show the crash caused the harm you are claiming. Glossary: how much of your current pain, treatment and limits the crash caused. Records from before and after the crash, and a doctor's comparison of the two, are usually the key evidence. A related rule, the Eggshell plaintiff rule. The rule that a person who causes an injury is responsible for all the harm it does, even if the injured person was unusually fragile, for example because of an old injury or an illness. Glossary rule, says the at-fault driver takes the injured person as they find them: someone more fragile than average can still recover for the full harm the crash caused. Our guides to back and neck injuries and whiplash explain how these claims are documented.
Example#
Related terms#
Questions people ask
Can I still make a claim if I had an old injury?
Yes, for the harm the crash added: new pain, new treatment and any lasting worsening. The dispute is usually over how much of your current condition the crash caused.
Will the insurer find out about my old injuries?
Often. Insurers commonly ask for prior medical records, and in a lawsuit the other side can request them through discovery. They are used to compare your condition before and after the crash.
Sources
- Judicial Council of California, Civil Jury Instructions (CACI), No. 3927 — aggravation of a preexisting condition
- Cornell LII Wex, Eggshell skull rule — liability for the full harm, however severe
- MedlinePlus Medical Encyclopedia, Cervical spondylosis — age-related changes in the neck
Last reviewed October 29, 2026 by the Accident Claim Facts editorial team. Found an error? Tell us.
Keep reading
- GlossaryGlossaryShort, plain-English definitions of the legal and insurance terms that come up after a crash, each with an example, related terms and the sources behind it.
- Injury typesBack and neck injuriesHerniated discs, sprains and spine fractures from crashes; what X-rays and MRIs can show; how claims handle age-related wear and old injuries; and independent…
- Injury typesWhiplashWhiplash is a soft-tissue injury of the neck, most often from rear-end crashes. How it is documented, and why insurers look hard at these claims.
- GlossaryPreservation letterA letter asking a person or company to keep specific evidence, such as driving logs, video or vehicle data, because a claim is likely.
- GlossaryPro hac viceLatin for "for this occasion." Permission from a court for a lawyer licensed in another state to take part in one specific case. Courts commonly require a…
- GlossaryProportionate responsibilityTexas's name for its comparative-fault system: the jury assigns each party a percentage of responsibility.