Legally Reviewed by William Pemberton on September 25, 2026
If you have pre-existing conditions, they can affect your Wisconsin personal injury claim, but not in the way you might fear. Under Wisconsin law, defendants are fully responsible for injuries they cause, even when those injuries are more severe due to their existing health conditions.
At Pemberton Personal Injury Law Firm, we have successfully represented countless clients with pre-existing conditions across Wisconsin. Our team understands how insurance companies attempt to exploit medical histories to reduce compensation. We fight to ensure every client receives full compensation for all injuries, regardless of their health before the accident. The truth is insurance companies will try to use your medical history against you, but Wisconsin’s legal framework protects injury victims with pre-existing conditions.
How Wisconsin Law Protects Injury Victims With Pre-Existing Conditions
Wisconsin follows a legal principle known as the “eggshell skull rule,” which was established in Wisconsin in the landmark 1891 case Vosburg v. Putney. In this case, a 12-year-old boy kicked another student in the shin during class. The seemingly harmless kick aggravated a pre-existing leg injury, ultimately causing permanent damage.
The Wisconsin Supreme Court ruled the kicking student liable for all resulting injuries, even though he did not know about the other boy’s existing condition. The court held that wrongdoers must “take their victims as they find them.”
This means defendants cannot reduce their responsibility simply because your body was more vulnerable to injury than the average person. Whether you have arthritis, a previous back injury, diabetes, or any other condition, the person who caused your accident is liable for the full extent of harm they cause.
What Compensation Can You Recover?
When someone injures you and aggravates a pre-existing condition, you can pursue compensation for all damages directly caused by the accident. The defendant is not responsible for your underlying condition itself. Instead, they are liable for any worsening of that condition caused by the accident.
For example, if you had chronic back pain before a car accident but the collision caused a herniated disc requiring surgery, the at-fault driver owes compensation for the herniated disc and related treatment.
You may be entitled to recover the following damages:
- Medical bills for the treatment of the aggravated injury
- Lost wages from missed work due to the worsened condition
- Pain and suffering related to the additional harm caused by the accident
- Future medical expenses if the aggravation requires ongoing care
Typically, a lawsuit must be filed within three years from the date of the injury, and this same three-year period generally applies regardless of whether the injured person had pre-existing conditions. However, there are important exceptions and nuances that can affect the applicable deadline.
How Insurance Companies Will Try to Use Your Medical History
Despite clear legal protections, insurance adjusters often attempt to minimize claims involving pre-existing conditions. They may argue your current symptoms stem entirely from your existing condition rather than the accident. They might claim the accident merely revealed a condition you already had, or that your injuries would have occurred regardless of their client’s actions.
Thorough documentation is your strongest defense. Keep all medical records from before and after the accident, maintain detailed notes about how your condition has changed, attend all medical appointments, and follow your treatment plan exactly as prescribed. Your attorney can work with medical experts who can testify about how the accident specifically aggravated your condition.
The Importance of Full Disclosure
Never hide your medical history from your attorney. While it might feel tempting to downplay prior injuries, full transparency is critical to building a strong case. Your medical records will surface during the legal process, and any appearance of dishonesty can damage your credibility.
When you openly discuss your health history with your lawyer, they can develop strategies to address these issues proactively. This includes explaining to insurance companies and juries how your condition made you more vulnerable to serious injury, demonstrating the specific ways the accident worsened your health, and ensuring all damages truly caused by the accident are properly documented.
Why Early Legal Guidance Matters in Cases Involving Pre-Existing Conditions
The earlier you consult with a Wisconsin personal injury attorney, the better your chances of maximizing your compensation. Early involvement allows your lawyer to preserve critical evidence before it disappears, communicate with insurance companies on your behalf to prevent damaging statements, arrange for proper medical evaluations that document the aggravation of your condition, and build a comprehensive case strategy.
Insurance companies promptly investigate claims involving pre-existing conditions. They will scrutinize your medical records, interview witnesses, and develop arguments to minimize their liability. Having an attorney levels the playing field and ensures defendants are held fully accountable for the harm they cause.
Contact Pemberton Personal Injury Law Firm to Fight for Fair Compensation
Pre-existing conditions do not disqualify you from pursuing fair compensation after an accident. Wisconsin law recognizes defendants must accept responsibility for the full extent of injuries they cause, regardless of their underlying health. The key is proving the connection between the accident and the aggravation of your condition.
If you have been injured in an accident and are concerned about how your pre-existing conditions might affect your claim, contact Pemberton Personal Injury Law Firm. Our team understands Wisconsin’s personal injury laws and knows how to protect clients with complex medical histories.
Frequently Asked Questions: Pre-Existing Conditions and Personal Injury Claims in Wisconsin
What is the eggshell skull rule and how does it apply in Wisconsin?
The eggshell skull rule is a legal doctrine that holds defendants fully responsible for all injuries they cause, even if those injuries are more severe than expected because of the victim’s pre-existing condition. The name comes from the concept that if you cause harm to a person with an unusually fragile skull, you are still liable for all resulting damage — you must take the victim as you find them. In Wisconsin, this rule was established in the 1891 case Vosburg v. Putney and has been applied consistently in personal injury cases ever since. It prevents defendants from escaping liability simply because the plaintiff’s body was more vulnerable to harm.
Can an insurance company use my past medical records against me in a personal injury claim?
Yes, insurance companies regularly request and scrutinize prior medical records in personal injury claims. Their goal is to argue that your current symptoms existed before the accident or that the accident did not worsen your condition. They may attempt to attribute your pain or limitations entirely to a pre-existing diagnosis rather than the crash. This is why full transparency with your attorney is so important. Your lawyer can work with medical experts to document precisely how the accident changed your condition, counter the insurance company’s narrative, and ensure that any compensation reflects only the damages the defendant caused.
What happens if the accident made a pre-existing injury worse?
If an accident aggravates a pre-existing injury, the at-fault party is liable for the worsening of your condition, not the underlying condition itself. For example, if you had a prior back injury that was well-managed before the accident, and the accident caused a new disc herniation or required surgery you would not otherwise have needed, the defendant is responsible for those additional medical costs, the lost wages during recovery, and the pain and suffering associated with that specific aggravation. The challenge is distinguishing what was pre-existing from what the accident caused — which is where medical expert testimony and thorough documentation become critical.
Should I tell my attorney about a pre-existing condition even if it seems unrelated?
Yes, always disclose your full medical history to your attorney. Even conditions that seem unrelated to your current injuries may surface during the legal process because the defense will request your medical records. If your attorney does not know about a prior condition, they cannot prepare for it, and unexpected disclosures can damage your credibility. Full transparency allows your attorney to build a proactive strategy that addresses pre-existing conditions head-on, explains how the accident was the cause of your new or worsened injuries, and prevents the opposing side from using your history as a surprise tactic to undermine your case.
How do medical experts help prove that an accident aggravated a pre-existing condition?
Medical experts play a central role in pre-existing condition cases. They review your medical records from before and after the accident to establish a clear baseline for your health before the injury occurred. They can then testify about how the accident changed your condition — for example, by identifying new imaging findings, a change in your diagnosis, or the need for treatments you did not require before. Neurologists, orthopedic surgeons, pain management specialists, and life care planners are among the experts commonly used in these cases. Their opinions provide the factual foundation for proving that the defendant’s actions specifically caused the harm for which you are seeking compensation.
ABOUT THE ATTORNEY
William Pemberton
Personal Injury Attorney, Pemberton Personal Injury Law Firm
William Pemberton is the founding attorney of Pemberton Personal Injury Law Firm, representing injured Wisconsinites across Madison, Eau Claire, Baraboo, Fitchburg, and Sun Prairie. He handles car accidents, motorcycle accidents, dog bites, brain injuries, and wrongful death cases on a contingency fee basis.
