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CategoriesCan an Old Injury Ruin Your Claim?
August 24, 2026
After a car accident or another serious injury, many people worry that an old injury or medical condition will prevent them from recovering compensation. If you’ve had back pain for years, injured your knee playing sports, or have arthritis, you may assume the insurance company will simply blame all of your pain on those existing issues.
However, Missouri law focuses on whether the accident aggravated or worsened your condition, not whether you had a medical issue beforehand. A pre-existing condition does not automatically prevent you from pursuing compensation.
If you’re concerned that an old injury could affect your claim, contact a personal injury attorney at Cofman Townsley for a free case review.
Missouri’s Eggshell Plaintiff Rule
Missouri follows what’s known as the Eggshell Plaintiff Rule, sometimes called the thin skull rule. Under this rule, the person responsible for the accident must “take the injured person as they find them.” In other words, they may still be responsible if the accident worsened an existing condition.
For example, two people may be involved in the same rear-end collision. One suffers only minor soreness, while the other has a pre-existing back injury that is aggravated by the crash and requires surgery. Even though the second person was more susceptible to injury, the at-fault driver may still be liable for the additional harm caused by the accident.
The important question isn’t whether you had a pre-existing condition. It is whether the accident made that condition worse. Medical records play an important role in demonstrating how your condition changed after the accident.
Common Pre-Existing Conditions That Can Be Aggravated
Many people lead active lives despite previous injuries or chronic medical conditions. A traumatic accident can turn a manageable condition into one that causes ongoing pain and limitations.
Some common examples include:
| Pre-Existing Condition | Before the Accident | After the Accident |
| Degenerative Disc Disease | Occasional stiffness | Chronic neck or back pain |
| Prior Knee Injury | Active with no significant limitations | Limited mobility or need for surgery |
| Previous Back Injury | Controlled with therapy | Severe pain requiring surgery or injections |
| Arthritis | Mild joint discomfort | Pain and reduced movement |
| Old Neck Injury | Stable with little treatment | Persistent pain and decreased range of motion |
In these situations, the accident didn’t create the original condition, but it may have worsened it.
How Insurance Companies Use Pre-Existing Conditions
Even when an accident clearly makes an existing condition worse, insurance companies may argue that your symptoms were caused by your prior injury instead.
An insurance adjuster may attempt to:
- Claim your pain existed before the accident
- Argue that your symptoms are part of the natural aging process
- Review years of medical records, looking for previous complaints
- Suggest the accident was too minor to cause your current injuries
- Point out gaps in medical treatment to question whether your condition worsened
These arguments aim to minimize what the insurance company pays, not necessarily to reflect what happened.
Even if you had previous medical problems, the insurer cannot automatically deny your claim if the accident aggravated those conditions.
How to Strengthen Your Claim
If you have a pre-existing condition, careful documentation can help establish how the accident worsened your injuries.
Some important steps include:
- Be honest about your medical history. Trying to hide a previous injury usually creates more problems than it solves.
- Seek medical treatment as soon as possible after the accident.
- Tell your doctor exactly how your symptoms have changed since the accident.
- Continue following your treatment plan.
- Keep records that show your condition before and after the accident, including medical records, imaging studies, and physical therapy notes.
Medical records often provide the clearest evidence that your condition became worse because of the accident rather than from its natural progression.
Compensation That May Be Available
Missouri law allows injured victims to recover compensation for the additional harm caused when an accident aggravates a pre-existing condition, but not for the underlying condition itself or its natural progression.
In Miller v. Gulf, Mobile & Ohio Railroad Co., the Missouri Supreme Court recognized this principle, explaining that a negligent party may be held responsible for aggravating a pre-existing medical condition.
Depending on the circumstances, compensation may include:
- Additional medical expenses
- Future medical treatment
- Increased pain and suffering
- Lost wages from missed work
- Reduced earning capacity
- Reduced quality of life and inability to participate in everyday activities
The goal is to compensate you for the changes the accident caused to your condition, not to erase the fact that a prior injury existed.
Don’t Assume an Old Injury Prevents You From Filing a Claim.
If an insurance company is trying to blame your injuries on an old medical condition, an experienced personal injury attorney can help gather medical evidence, work with your healthcare providers, and demonstrate how the accident affected your life.
For more than 50 years, Cofman Townsley has helped injured Missourians stand up to insurance companies and pursue the compensation they deserve. Contact our team today for a free consultation to discuss your case.