Pre-Existing Conditions and the Eggshell Plaintiff Rule in New Hampshire

The Insurer's Favorite Defense

If you had any prior injury or medical condition, expect the insurer to argue that your current symptoms come from that, not the crash. Pre-existing conditions are one of the most common tools insurers use to reduce or deny injury claims, and the argument can sound persuasive on the surface.

But the law does not let a careless party off the hook simply because the person they injured was not in perfect health to begin with. The relevant question is not whether you had a prior condition — it is whether the crash caused new harm or worsened what was already there.

The Eggshell Plaintiff Principle

A long-standing principle, often called the eggshell plaintiff rule, holds that a wrongdoer takes their victim as they find them. If a crash aggravates a pre-existing condition or causes greater harm because of the person's particular vulnerability, the at-fault party is responsible for that full harm, not just the harm an average person would have suffered.

This means a herniated disc made symptomatic by a crash, or a prior injury made worse, can support a full claim even though the underlying condition existed before. The key is distinguishing the new or aggravated harm from the prior baseline.

Proving Aggravation

Establishing how the crash changed your condition is central. Prior medical records showing your baseline, treating physicians who can explain the worsening, and clear documentation of your symptoms before and after the crash all rebut the insurer's blanket blame-it-on-the-history defense. Honesty about your medical history, paired with skilled presentation, turns a perceived weakness into a manageable part of the claim.