PERSONAL INJURY; AGGRAVATION OF PREEXISTING CONDITION
A person who has a condition or disability at the time of an injury is not entitled to recover damages therefor. However, he is entitled to recover damages for any aggravation of such preexisting condition or disability [proximately] [legally] resulting from the injury.
This is true even if the person’s condition or disability made him more susceptible to the possibility of ill effects than a normally healthy person would have been, and even if a normally healthy person probably would not have suffered any substantial injury.
Where a preexisting condition or disability is so aggravated, the damages as to such condition or disability are limited to the additional injury caused by the aggravation.
NEV. J.I. 10.06