Anecdotal evidence suggests that patients who have life-threatening conditions often choose to undergo high-cost, high-risk treatments for them. This kind of risk-seeking behavior seems irrational because most patients are risk-averse. The Health Stock Risk Adjustment (HSRA) model seeks to explain this phenomenon. The model is based on the concept of relative health stock--the ratio of patients' expected quality-adjusted life years (QALYs) after a diagnosis to their expected QALYs before the diagnosis. The model predicts risk-averse patients will behave in a risk-seeking manner as their relative health stocks deteriorate. The HSRA model can help physicians better understand why some seriously ill patients seek high-risk treatments while others elect to forgo treatment. State legislatures and insurers are attempting to appropriately design insurance benefits for patients with life-threatening conditions. The HSRA model can help predict which patients will most likely take advantage of these benefits.