How to Handle Pre-Existing Conditions Without Losing Your Case
How to Handle Pre-Existing Conditions Without Losing Your Case
You're three months into a rear-end collision case. Your client has a solid story, a cooperative treating physician, and a defendant who was clearly texting. Then defense counsel sends you a records request and you realize — your client had back treatment two years before the crash.
Now you're waiting. Wondering if defense knows. Wondering if your client told you everything.
Here's the thing: defense counsel already knows. Or they're about to. And if you haven't addressed it first, you just handed them the only narrative they need.
I've been trying plaintiff PI cases for over 20 years — more than 40 to verdict. Pre-existing conditions come up constantly. They don't lose cases. How you handle them does.
Why This Is the Most Dangerous Defense Argument You'll Face
Defense lawyers love pre-existing conditions because they shift the story.
The case stops being about what the defendant did. It becomes about what your client is hiding.
That's the real play. They're not just arguing the injury was pre-existing. They're implying your client is lying — or that you're helping them lie. And once a jury starts thinking your client isn't being straight with them, you've lost the room.
The prior injury defense argument works because it creates doubt about credibility, not just causation. That's why it's so dangerous.
If the jury hears about your client's prior back treatment for the first time on cross-examination — or worse, through defense counsel's opening — you've already lost the framing battle. You're playing catch-up for the rest of the trial.
The only way to win this is to own it first.
The Right Approach: Inoculate Early, Frame It as Aggravation
The legal concept you need here is aggravation of a pre-existing condition. This isn't some creative workaround — it's a well-established, jury-friendly principle. A defendant takes a plaintiff as they find them. If your client had a vulnerable back and the crash made it significantly worse, that's a real injury. The defendant is responsible for the aggravation.
But the legal concept alone isn't enough. You need to build it into your story from the start.
Step one: Get ahead of it before discovery closes.
Don't wait for defense to surface it. Pull the records yourself, understand exactly what your client had going on before the crash, and make it part of your case theory early. The moment you know about a prior injury, start building the aggravation frame.
Step two: Use your client's voice.
Get your client comfortable explaining it. Not defensively — matter-of-factly. Something like: "Yeah, I had some low back issues a few years ago. I went to physical therapy, it got better, I was back to normal. This crash is completely different. I've never had pain like this."
That's your client owning it. Clean, credible, done.
Step three: Put it in your opening.
Don't save this for direct examination. By the time your client takes the stand, the jury should already know about the prior injury — from you. You told them. That's different from defense "exposing" it. When you tell them, it's transparency. When defense tells them, it's a bombshell.
This is the core of inoculation: you take their best shot away by throwing it yourself.
A Real Example: The Rear-End Collision With Prior Low Back Treatment
Here's a case type that comes up constantly.
Maria, 42, is stopped at a red light when she gets rear-ended by a delivery driver going 35 mph. She goes to the ER, then starts treating with an orthopedic specialist. MRI shows a herniated disc at L4-L5. She's in significant pain, stops being able to do the landscaping work she runs on weekends, and needs an epidural injection series.
Defense pulls her records and finds she was treated by a chiropractor three years ago for low back soreness — about eight sessions over two months. She'd mentioned it to you, but minimized it. "Just some tightness, it went away."
Here's how to handle it.
On direct, you ask her about it directly. "Before this crash, had you ever had any back issues?" Let her explain it in her own words. She went to the chiropractor for some muscle tightness after a long move, it resolved completely, she hadn't thought about it in three years. Life was normal. She was hauling mulch bags on weekends without any problem.
Then you get her treating doctor to draw the line. The prior treatment was soft tissue, muscular. What she has now is a structural herniation with nerve involvement. These are not the same injury. The crash caused the herniation. The question isn't whether she had any prior history — it's what the crash did to her that wasn't there before.
In opening, you tell the jury straight up: "You're going to hear that Maria had some back soreness years ago. She did. She went to a chiropractor, it got better, and she moved on with her life. What you're also going to hear is that this crash gave her something she never had — a herniated disc that's been causing her serious pain for 18 months. Those are two completely different things. Defense is going to try to blur that line. Don't let them."
Now defense has nothing. The jury already heard it from you. When defense brings it up, they look like they're pointing to something you already acknowledged. You've neutralized their sharpest tool.
Common Mistakes That Lose You the Case
Hiding it. Some lawyers hope defense won't find it, or won't make an issue of it. That's wishful thinking. They will find it. And if it comes out at trial without you having addressed it, your client looks like they were hiding something. So do you.
Minimizing it too hard. There's a difference between putting the prior injury in context and pretending it doesn't matter. If you wave it off — "it was nothing, totally unrelated" — without actually explaining why, it sounds defensive. Jurors can tell when you're uncomfortable. Walk through it. Explain the difference between what she had before and what she has now.
Waiting until direct examination. By the time your client takes the stand, the jury has already heard defense counsel's opening. If they mentioned the prior injury there — and they will — the jury is watching your client's testimony through a skeptical lens. You needed to address it in your opening, before that lens was applied.
Letting the client downplay it in their intake. This is a process problem. When you first meet a client, ask specifically about prior treatment to the same body part. Not just "any health issues" — get specific. If there's prior treatment, you need to know about it when you're building the case, not when defense serves their interrogatories.
Takeaways
- Pull the prior records yourself, early. Don't wait for defense to surface them. Know what you're dealing with before you've built a strategy that ignores it.
- Frame it as aggravation from the start. The legal concept exists. Use it. Your client's story is about what the crash added — not what they had before.
- Inoculate in opening. Tell the jury about the prior injury before defense does. When you own it, it's not a bombshell. It's context.
- Prepare your client to own it on direct. They should be able to explain the prior injury clearly, calmly, and in plain language. Practice this. "Yeah, I had some back issues — it resolved. This is different."
- Get your medical expert to draw the line. Soft tissue vs. structural herniation. Resolved vs. ongoing. Same area of the body, completely different conditions. That distinction needs to come from a credible medical voice, not just your client.
The Bigger Picture
Pre-existing condition cases are not unwinnable. I've gotten strong verdicts on cases where the client had more prior history than I would have liked.
What kills these cases isn't the prior injury. It's the silence around it. When you treat a prior injury like something to hide, you're teaching the jury to treat it that way too — as something suspicious.
When you own it, explain it, and contextualize it with the right framing, it becomes just another fact in a case about what the defendant did.
The defendant made a choice. That choice hurt someone who was already a little more vulnerable. They're responsible for the harm they caused — all of it.
That's your story. Tell it first.
Want to go deeper on this? Read How to Use Inoculation in Your Opening Statement — the full framework for defusing defense arguments before they land.