How to Win a Personal Injury Case With a Pre-existing Condition

You've been hurt in an accident. You go to the doctor, file a claim, and then the insurance adjuster's tone suddenly shifts. They've been digging through your medical records, and they've found something: a prior back surgery, a history of arthritis, an old neck injury from years ago. Now they're suggesting your current pain isn't really from this accident. It's your "pre-existing condition."

This is one of the most common—and most effective—tactics insurance companies use to minimize or deny compensation to injured people. And for many victims, it works. They accept a lowball settlement or walk away entirely, not realizing that every state has a law that provides meaningful protections for exactly this situation.

But here’s what you should know:

A pre-existing medical condition doesn’t disqualify you from receiving full compensation for an injury caused or worsened by someone else’s negligence.

Understanding this concept could make the difference between a fair and full recovery and a denied claim.

What is a pre-existing condition?

In the context of personal injury law, a pre-existing condition is any medical issue, injury, or health condition that existed before the accident or incident that’s the subject of your claim.

The term covers a wide variety of issues that include (but are not limited to):

• Prior surgeries (for example, back surgery, knee replacement, rotator cuff repair)
• Chronic conditions such as arthritis, degenerative disc disease, or osteoporosis
• Old injuries that healed but left residual weakness or vulnerability
• Ongoing conditions such as diabetes, fibromyalgia, or migraines
• Mental health conditions including anxiety, depression, or PTSD
• Age-related degeneration of bones, joints, or soft tissue

The reality is that a large proportion of the population lives with underlying health issues that don’t significantly affect their daily lives. But when an accident happens, that can change in an instant. An older adult who has a “bad back” with occasional flare-ups that are generally treated with over-the-counter pain medication might become debilitated after a rear-end car crash. A person who has occasional knee pain might require surgery after a slip-and-fall accident that aggravated the condition. Many people have underlying joint, spine, or age-related conditions that are asymptomatic until they’re aggravated by trauma.

The Eggshell Skull Rule

Yes, you read that correctly. The Eggshell Skull Doctrine exists in some version in every state; it protects plaintiff injury victims with pre-existing conditions. It’s named for a classic law school hypothetical: A plaintiff with a skull as fragile as an eggshell is injured. The defendant’s negligence causes contact with the plaintiff’s head that would be trivial for a typical person—they would recover with no lasting repercussions. But the injury to the “eggshell plaintiff” results in catastrophic brain injury. The defendant is then fully liable for all resulting damages. 

The core principle of this doctrine is that the defendant must take the plaintiff as they find them. In other words, the defendant is fully responsible for all consequences of their negligence, even if the victim’s unique vulnerability made the consequences more severe than the defendant could have anticipated.

Limitations to the Eggshell Skull Doctrine

Although the Eggshell Skull Doctrine helps plaintiffs in many instances, there are situations that are not covered under the rule:

• You cannot be compensated for the pre-existing condition itself. The rule protects your right to recover for the aggravation or worsening of a pre-existing condition. It does not cover the underlying condition that existed before the accident. For instance, if you had a herniated disc prior to a car accident, you cannot recover compensation for that disc as it was before the crash. You may recover for the extent to which the accident made it worse.
• Unrelated conditions are generally not recoverable. If the accident reveals an entirely unrelated health problem, the defendant isn’t responsible for treating it. For example, you were in a car accident and had X-rays in the hospital afterwards. The X-ray displayed a tumor; this was not caused by the accident, it was discovered because of the post-accident examination. The rule only applies to harm that was causally connected to the defendant’s negligence. 
• Spontaneous flare-ups aren’t covered. If a pre-existing condition worsens on its own, unrelated to the accident, the rule does not apply. Some states’ courts require that the plaintiff demonstrate that the defendant’s negligent act directly caused a new injury or worsened an existing one.

How insurance companies use a pre-existing condition against you

If you read nothing else about how to have a successful lawsuit, read this. It matters, particularly if you have a pre-existing condition. Remember, whether you’re pursuing a defendant’s insurer or you’ve filed a claim with your own insurance company—the insurer is not on your side. The insurance company’s objective isn’t to make sure you receive the compensation you need to cover your injuries. Its objective is to make money. And the more money it pays out to you as a settlement after an accident, the less it keeps for itself. The insurer is in this for its bottom line, not yours. 

However, an experienced personal injury lawyer can help you receive the compensation you need and deserve. Still, keep these points in mind as you move forward with an insurance claim. 

Here’s how the insurance company will use your pre-existing condition to deny or lowball your claim.

Mining your medical records

An insurance company will typically examine your medical records for about three to five years prior to the claim. For a high-value claim, it might request records from even further back. Adjusters are looking for previous diagnoses, complaints, or treatments they could use to argue that your current symptoms existed prior to the accident.

Demanding overbroad medical authorizations

An insurer will often push a claimant to sign a blanket release that authorizes access ot all past medical records. This can provide a sweeping view of your entire health history, far beyond what’s relevant to the accident. This allows them to search for anything that might undercut your claim. You’re not required to sign an authorization without legal review; your attorney can limit it to records that are genuinely relevant.

Cherry-picking records that misrepresent your condition

An adjuster might selectively pull records that indicate prior symptoms, while ignoring evidence of how the accident changed your condition. They might claim arthritis or disc degeneration “caused” your pain, but ignore the medical reality that trauma can transform a manageable degenerative condition into a disabling injury.

Arguing the injury was inevitable

You might have been living and working normally prior to the accident. Insurers could argue that your condition would have deteriorated over time, regardless of the accident. This would mean the accident isn’t really the reason for your current suffering. This argument is legally weak, but psychologically effective—but lawyers are wise to this, which is why it’s crucial to have legal counsel if you have a pre-existing condition.

Making an early settlement offer

This might sound beneficial, but it’s not. Insurance companies know that some injuries—including the impact of an aggravated pre-existing condition—take weeks or months to fully manifest. They might make a quick offer specifically to capture your signature on a release before you understand how serious your condition is. Once you sign a release, you typically may not seek additional compensation, regardless of how your condition evolves.

How to build a strong case when you have a pre-existing condition

1. Be honest about your medical history. Don’t try to hide a pre-existing condition. The insurance company will find it, and when they do, it will destroy your credibility when it comes to your injuries from the accident. Courts and juries tend to respond more favorably to plaintiffs who proactively acknowledge a prior condition and explain how the accident made it worse. Transparency is both ethically required and strategically superior. 
2. Seek immediate medical care and follow your treatment plan. It’s crucial that you see a doctor as soon as possible after an accident. This creates a clear medical record that links your current condition to the accident. The longer you wait to document your injuries, the more difficult it is to prove that they were directly caused by the accident. You must also follow your treatment plan. That means attending appointments, completing prescribed therapy, taking medications as directed, and making any other lifestyle changes indicated by the provider. This is essential for demonstrating the severity of your injury and protecting the credibility of your claim. 
3. Gather thorough medical documentation from before and after the accident. The contrast between your medical records before and after the accident could be the most powerful evidence in a pre-existing condition case. Records that show your back problem was “stable and manageable” before the accident, followed by records that document new symptoms, escalating treatment, and surgical intervention after the accident, tell a compelling and objective story. 
4. Obtain expert medical testimony. A qualified medical expert who can testify about how the accident specifically aggravated your pre-existing condition is crucial. An expert can distinguish between symptoms attributed to your pre-existing condition and those that are new or worsened as a result of the accident. This is exactly the type of nuanced analysis that can break down the insurance company’s argument. 
5. Maintain a detailed journal. Aside from medical records and bills, it’s helpful to keep your own notes or entries that document how the injuries affect your daily life. Document your pain levels, limitations, missed activities, and daily struggles. Start these notes as soon as possible after the accident. The court can apportion damages between the pre-existing condition and the worsening caused by the accident. Your written account of how your life has changed can be powerful evidence of the actual impact of the injuries. 
6. Do not provide a recorded statement. Rather, don’t do this without consulting your attorney first. An insurance adjuster is trained to use seemingly innocuous recorded statements against you. These are common insurance company tactics designed to minimize your injuries. It could even be phrased like small talk (“How are you doing today?”) that elicits a response like, “I’m doing fine.” You might think “fine” means you’re doing the same as you’ve been, while dealing with ongoing pain. But they can interpret that “fine” to mean that you’re not in pain at all. You’re fine. While it might seem benign to you, these statements can be weaponized to deny or lowball your claim. You’re not typically required to provide a recorded statement to the insurer, and you should never do so without counsel from your attorney.

Ultimately, a pre-existing condition is not a barrier to fair compensation. But it is an obstacle, and it requires careful strategy and experienced legal guidance to overcome. The law recognizes that people should not be penalized for their vulnerabilities, and a negligent individual does not get to escape consequences because the plaintiff is more vulnerable than the average person. 

The insurance company knows the law—and so does your lawyer. But unrepresented clients aren’t as well-versed, and they tend to have worse outcomes and less compensation than those who are represented by an experienced personal injury attorney. If you were injured and you have a pre-existing condition, the most important step you can take is to consult with a personal injury lawyer who understands how to build a claim around your complete medical picture, counter the insurance company’s arguments, and fight for the full compensation you’re legally entitled to receive.