Identify diseases with idiopathic, iatrogenic, and multifactorial causes, and discuss the importance of identifying risk factors for diseases

Review the following case study and discuss the question that follows.
1.TL is a 62-year-old male who was in a car wreck and who has been hospitalized for compartment syndrome from a left leg crush injury. He has areas of necrosis (tissue ischemia) seen along his calf. Tissue necrosis is areas of dead cells. It is imperative that the necrosis does not increase.
a). Discuss#1
The etiologies of cellular injury and death and what can be done for TL to maximize his care.
b)Discussion #2
Identify diseases with idiopathic, iatrogenic, and multifactorial causes, and discuss the importance of identifying risk factors for diseases. Explain how measurements of structural, physiologic, biochemical, and genetic parameters provide a basis for disease screening and identification of risk factors.
References : textbook : Pathophysiology,5th edition, Lee-Ellen Copstead-Kirkhorn, Jacquelyn L. Banasik.