After a car accident, most people worry about brand-new injuries. However, what happens if the accident makes an existing medical condition worse? If you already had back pain, arthritis, or a previous neck injury, and a car crash intensified that pain or made your daily life harder, you may be wondering if you still have a case. The short answer is yes, you do. But it can get complicated.

At Mesadieu Law Firm, we understand how an accident can impact your life in ways others might not see. That’s why we created this guide—to explain how preexisting conditions affect personal injury claims and what your rights are if a car accident aggravates a previous condition.

 Understand Preexisting Conditions

First, let’s define what we mean by a preexisting condition. A preexisting condition is any medical issue you had before the accident. These conditions can be chronic, like arthritis, or injury-related, like an old knee surgery or a past spinal injury. Some common examples include the following:

• Degenerative disc disease
• Herniated discs
• Prior concussions or brain injuries
• Osteoarthritis
• Fibromyalgia
• Past fractures or surgeries
• Anxiety or PTSD

You might have lived with one of these conditions for years, managing symptoms with treatment or lifestyle changes. Then, out of nowhere, a car accident happens—and suddenly your symptoms get worse. This is where your legal rights come into play.

How Car Accidents Can Make Preexisting Conditions Worse

Although you may not suffer a brand-new injury, a crash can make an existing condition much more painful or difficult to manage, which may include the following:

• A herniated disc that was once manageable may become debilitating.
• Old knee pain could return with swelling and limited mobility.
• Anxiety that was under control could escalate after a traumatic collision.

Doctors call this exacerbation or aggravation of a preexisting condition. Insurance companies call it something else: a reason to deny your claim or minimize your compensation. That’s why it’s important to understand your rights and how to protect them.

The “Eggshell Skull” Rule: Why the Law Protects You

Under New York personal injury law, there’s a legal principle called the “eggshell skull” rule. This rule says that the at-fault party must take the victim as they find them. In other words, if a person has a preexisting condition that makes them more vulnerable to injury, the person who caused the accident is still fully responsible for the consequences.

Let’s say someone rear-ends you, and your mild back pain becomes a severe problem. The law doesn’t let them off the hook just because you weren’t in perfect health before the crash. They are still liable for the damages caused by their actions—even if the same impact wouldn’t have hurt someone else as badly.

 Challenges in Proving Aggravation of a Preexisting Condition

Even though the law is on your side, you may still face challenges in your personal injury claim.

Insurance companies often try to argue that

• Your current pain is just part of your existing condition.
• The accident didn’t cause any new damage.
• You’re exaggerating your symptoms.

This is why it’s essential to have strong medical documentation and legal representation. A skilled personal injury lawyer can help prove that the accident made your condition worse—and that you deserve compensation for the increased pain, treatment, and impact on your daily life.

What You Can Do to Strengthen Your Case

If you have a preexisting condition and you’ve been in a car accident, here are steps you should take right away:

1. Get Immediate Medical Attention

First and foremost, see a doctor—even if you think it’s “just” a flare-up of your usual symptoms. Only a medical professional can evaluate whether your condition has worsened. More importantly, getting this on record creates documentation that your lawyer can use later.

2. Be Honest About Your Medical History

Don’t try to hide your condition. Insurance companies will dig into your past medical records, and if they find out you weren’t honest, it could hurt your claim. Instead, be upfront with your doctor and your lawyer. Honesty helps you build a stronger case.

3. Keep Track of Symptoms and Limitations

Start a journal. Write down how you feel each day, what activities you can or can’t do, how your condition has changed, and what new treatments or medications you’re taking. This personal record can back up your claim and show the real impact of the accident.

4. Follow All Medical Advice

Stick to your treatment plan, attend follow-up appointments, and take your medications. If you ignore your doctor’s orders, the insurance company may claim that you’re not really injured or that you made your condition worse on your own.

5. Call a Personal Injury Attorney Right Away

Don’t wait. The sooner you get a lawyer, the better your chances of building a strong case. At Mesadieu Law Firm, we work with medical experts to prove how your condition was aggravated and what kind of compensation you deserve.

What Kind of Compensation Can You Get?

If you can prove that the accident made your condition worse, you may be entitled to compensation for the following:

• Medical bills – for both past and future treatment
• Lost wages – if you can’t work because of increased symptoms
• Pain and suffering – for the added discomfort and disruption
• Reduced quality of life – if your condition limits your mobility, sleep, or enjoyment of life

Your compensation should reflect the full extent of how the accident has affected you—not just your preexisting condition, but how much worse it’s gotten.

Why Insurance Companies Fight These Claims

Insurance companies are businesses. Their goal is to pay as little as possible. When they see a claim involving a preexisting condition, they often try to

• Blame all your symptoms on the old injury
• Demand access to years of medical records
• Use expert opinions to downplay your aggravation

That’s why having an experienced lawyer matters. We know their tactics, and we know how to fight back.

Real-World Example

Let’s say you had a history of lower back pain from years ago. It was mild and under control with stretching and the occasional chiropractor visit. Then, after a T-bone accident at a Bronx intersection, you start experiencing sharp pain, numbness down your legs, and trouble walking.

You need physical therapy, MRIs, and maybe even surgery.

The insurance company says, “Your back was already bad.” But the reality is: your life is very different now because of that crash. And legally, the person who hit you is responsible for that difference.

At Mesadieu Law Firm, we make sure that difference is not overlooked or minimized. We help you prove it.

Do You Need to File Quickly?

Yes. In New York, there are strict deadlines for filing personal injury claims—usually three years from the date of the accident. However, waiting can hurt your case. Memories fade, evidence disappears, and medical records become harder to collect. The earlier you act, the stronger your case will be.

Final Thoughts: Don’t Let a Preexisting Condition Stop You

Too often, accident victims assume they don’t have a case because of a prior condition. But the law doesn’t work that way—and neither do we. You still have rights. You still deserve compensation if someone else’s negligence made your life harder.

At Mesadieu Law Firm, we treat every client with care and respect. We fight for people with complicated medical histories because we know the truth: an aggravated condition is still an injury.

Need Help After a Car Accident?

If a car accident has worsened a previous condition, don’t assume you have no legal options. Instead, call 844-3-RIGHT-BY-YOU (844) 374-4482. Mesadieu Law. Right By You.