Earliest (clinically reversible stage): Fatty streak - Grossly: yellow intimal streak and characterized - Microscopically: lipid-laden macrophages (foam cells)

- Stable atheromatous plaques: Dense fibrus cap, small lipid core, less inflammation. Cause chronic ischemia.

- Vulnerable atheromatous plaques: At risk for rupture, thrombosis or embolization due to composition (thin fibrous cap, large lipid core, dense inflammation).