Causation in Personal Injury Lawsuits

Personal Injury

One of the essential elements a plaintiff in a personal injury lawsuit must prove is causation. This means that the plaintiff must show that the defendant’s conduct was the actual and proximate cause of their injury. While actual cause is relatively straightforward, proximate cause can be more difficult to prove.

Actual cause, or “cause in fact,” simply means that the defendant actually caused the plaintiff’s injury. For instance, if a car runs a red light and hits your car, the driver’s actions are the actual cause of any injuries you suffer from the accident. 

Proximate cause is often referred to as “legal cause” and designates the cause that the law recognizes as the primary cause of the injury. A sequence of events may cause an injury, and proximate cause may be any one of the events in that sequence. A proximate cause is an act that can foreseeably lead to an injury on its own, without intervention from another person or cause. Thus, an action is a proximate cause if the plaintiff’s injury were the natural and foreseeable consequence of the action, and the injury could not have occurred without it. 

There are two tests for determining whether a defendant’s action was the proximate cause of the plaintiff’s injuries: the “but for” test and the “substantial factor” test. If you are considering pursuing a personal injury claim, you should consult an attorney to determine which test the courts in your state use. 

The “But For” Test

The “but for” test is met if the plaintiff’s injury would have occurred but for the defendant’s conduct. This test involves balancing the probabilities of all the factors leading to an injury. If any other factor could have let to the plaintiff’s injury had the defendant’s action not occurred, the claim will fail this test.

In the example above where the driver ran a red light and hit your car, the driver’s actions satisfy the “but for” test because you would not have been injured had the driver not run the red light. However, it is important to note that a defendant will not be liable for any unforeseeable effects of their conduct. Therefore, if the driver had instead run into a building where explosives were manufactured, the driver’s actions would not be the proximate cause of any damage from the explosives, because that is not a foreseeable result of running a red light. 

The “Substantial Factor” Test 

The “substantial factor” test is met if the defendant’s conduct was a substantial factor in bringing about the plaintiff’s injury. The substantial factor test is used when multiple forces combine to cause the plaintiffs’ injury and any one of them on its own would have been sufficient to cause the injury. A factor is substantial if it was material to causing the injury and was in operation up until the point in time that the injury occurred. If the defendant’s action was one of several factors that led to the plaintiff’s injury, but was a substantial factor in bringing it about, it will be deemed the proximate cause of the injury. As with the “but for” test, a defendant will not be liable for any unforeseeable results of their conduct under the substantial factor test.

Thanks to Eglet Adams for their insight on causation in personal injury lawsuits.