“Causation”, Preexisting Conditions, and Later Negligence
Published .
The general concept
A claimant must prove causation: that the defendant’s conduct actually contributed to the injury and that the law treats the connection as sufficiently close. The “take your victim as you find them” principle means a defendant generally cannot avoid responsibility merely because the injured person was unusually vulnerable. A preexisting condition does not erase responsibility for a new injury or an aggravation caused by the defendant.
How Maryland applies it
The claimant must still separate, when the evidence permits, the harm caused by the event from symptoms or limitations that would have existed anyway. Medical history is relevant to that comparison, but a prior condition is not an automatic defense. A later negligent act does not automatically cut off the first defendant’s responsibility. In Maryland, a later act is more likely to be a superseding cause when it is sufficiently independent and extraordinary that the original harm is no longer a proximate cause; foreseeable medical treatment or ordinary responses to an injury may leave the original causal chain intact. A later provider may also be responsible for additional harm caused by that provider’s own negligence. Whether damages can be divided, and which defendants must pay, depends on the proof, the nature of the injury, and Maryland’s rules on joint tortfeasors and contribution.
Related Maryland Cases and Authorities
B.G. & E. v. Lane, 338 Md. 34 (1995).; Copsey v. Park, 453 Md. 141 (2017).; Maryland Pattern Jury Instruction—Civil 19:10 (proximate cause).