What Is Causation?

In a personal injury claim, causation is the legal requirement that the defendant’s conduct actually caused your injury. Without it, there is no liability regardless of how carelessly someone behaved. Texas law requires proof of two distinct types of causation in every negligence case: actual cause and proximate cause.

Why Causation Is Required in Legal Claims

Causation is a required element of any negligence-based personal injury claim. A defendant can only be held responsible if their conduct is directly tied to the harm you suffered. Even the most careless behavior cannot result in a damages award without that connection.

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The Two Types of Causation in Texas Law

Texas courts require plaintiffs to establish both forms of causation before liability can attach:

• Actual cause: Also called “cause in fact,” this asks whether the injury would have occurred but for the defendant’s conduct.
• Proximate cause: This examines whether the harm was a foreseeable result of the conduct, not an outcome too remote or indirect to hold the defendant responsible.

Actual cause addresses what happened in the real world, while proximate cause draws a boundary around how far legal responsibility can extend.

How Actual Cause Works

The actual cause is most often analyzed through the “but-for” test, which questions whether the injury would have happened but for the defendant’s actions. If the answer is no, the actual cause is satisfied. For example, if a driver runs a red light and hits another vehicle, the collision would not have occurred but for that traffic violation.

When multiple factors contribute to an injury, courts may apply the “substantial factor” test instead, allowing causation to be established when a defendant’s conduct played a meaningful role in producing the harm, even if it was not the sole contributor.

How Proximate Cause Works

Proximate cause limits liability to harms that were reasonably foreseeable at the time of the negligent act. A chain of events that is too attenuated or unexpected falls outside the scope of legal responsibility. Two concepts anchor this analysis:

• Foreseeability: Whether a reasonable person could have anticipated that the conduct might cause this type of harm.
• Directness: Whether the chain of events connecting the conduct to the injury is sufficiently close to justify liability.

For example, if a driver runs a red light and strikes another vehicle, it is entirely foreseeable that the collision could cause injuries to the other driver. However, if that same driver ran a red light, startled a bystander on the sidewalk, who then dropped a bag that tripped someone half a block away, the connection between the driver’s conduct and that final injury is likely too remote and indirect to establish proximate cause.

Evidence Used to Prove Causation

Courts need substantive proof that ties the defendant’s specific conduct to your specific injury. Evidence that commonly supports a causation argument includes:

• Medical records: Documenting how the injuries relate to the incident in question.
• Expert testimony: Explaining scientific, medical, or technical connections that are beyond common knowledge.
• Witness statements: Describing how the event unfolded from firsthand perspectives.
• Physical evidence: Demonstrating the force, impact, or conditions that produced the harm.
• Accident reports: Providing official documentation of the incident at the time it occurred.

Common Challenges to Causation Arguments

Causation is frequently the most contested element in a personal injury case. Defense attorneys often focus their arguments here because a successful challenge can defeat a claim entirely, even when negligence is otherwise clear.

Frequent challenges include:

• Preexisting conditions: Arguing that the injury existed before the incident and was not caused by it.
• Multiple contributing causes: Suggesting that other factors were the true source of the harm.
• Lack of direct evidence: Contending that the connection between conduct and injury cannot be sufficiently proven.
• Time gaps: Raising doubt about whether the injury arose from this specific event or something else entirely.

Causation When Multiple Parties Share Responsibility

Accidents often involve more than one contributing party. When that happens, Texas law does not simply pick the “most responsible” defendant. Under Texas Civil Practice and Remedies Code § 33.001, Texas follows a modified comparative responsibility system. Fault is divided among all contributing parties based on their respective roles in causing the harm. A plaintiff’s own percentage of fault may also reduce their recovery.

Causation analysis is central to this apportionment; each party’s share of responsibility is tied directly to the extent of their conduct’s contribution to the harm.

Causation Versus Correlation

Correlation means two things happened around the same time or in connection with each other. Causation means one of them actually produced the other. Courts treat these as fundamentally different, and a personal injury claim requires the latter.

A common example is a plaintiff who visited a doctor for back pain two weeks before a car accident. The defense may argue that the back injury predates the crash. That the pain and the accident occurred close in time is a correlation. Whether the crash worsened or caused the injury is a causation question, and it requires medical evidence to answer, not just timing. Expert testimony is often what separates a documented causal link from a pattern that only looks connected on the surface.

Why Causation Is the Linchpin of a Personal Injury Claim

Building a causation argument starts at the scene. Medical documentation, incident reports, and witness accounts gathered in the days immediately following an injury are often what determine whether a claim can be proven. The stronger and earlier that evidence is secured, the harder it becomes for a defense to argue that the harm came from somewhere else.

FAQ: Causation in Texas Personal Injury Claims

What If My Injury Had Multiple Causes?

Texas law accounts for this. Under the substantial factor test, causation can be established even when the defendant’s conduct was one of several contributing factors, provided it played a meaningful role in producing the harm.

Can a Preexisting Condition Eliminate My Claim?

Not necessarily. Texas follows the “eggshell plaintiff” doctrine, meaning a defendant takes the plaintiff as they find them. If the accident aggravated a prior condition, the defendant can still be held liable for that aggravation (not the underlying condition). Medical records documenting your health before and after the incident carry significant weight in these situations.

Do I Need an Expert Witness to Prove Causation?

Not always, but in cases involving medical injuries or complex accident dynamics, expert testimony often bridges the gap between facts and legal proof. Courts may require it when the causal link is beyond what an average juror could assess without technical guidance.

What Is the Difference Between Causation and Negligence?

Negligence and causation are related but distinct legal concepts. Negligence refers to whether a person failed to act with reasonable care. Causation asks whether that failure actually produced the harm. A defendant can be negligent without being liable if their conduct did not cause the specific injury at issue. Both elements must be proven for a personal injury claim to succeed, which is why cases sometimes turn entirely on causation even when the negligent behavior itself is not in dispute.

Talk to Mokaram Injury Lawyers About Your Injury Case

Causation questions can make or break a personal injury claim. Our team at Mokaram Injury Lawyers is available around the clock, including after hours, unlike many firms. We offer free case reviews and take cases on a contingency basis, meaning you pay nothing unless we recover for you.

Call us at 281-222-2222 or contact us online to get started.