Arterial sclerosis (a.k.a. atherosclerosis) is an extremely common condition which can cause coronary thrombosis, myocardial infarction and other serious conditions.

The exact cause of atherosclerosis isn't known. However, studies show that atherosclerosis is a slow, complex disease that may start in childhood. It develops faster as you age. Atherosclerosis may start when certain factors damage the inner layers of the arteries. These factors include:
• Smoking • High amounts of certain fats and cholesterol in the blood • High blood pressure • High amounts of sugar in the blood due to insulin resistance or diabetes"

Source : US Govt. NIH

Other risk factors which are known to contribute to the onset of the disease include:

• Overweight or obesity.
• Lack of physical activity.
• Unhealthy diet.
• Ageing.
• Family history.