The causes of carotid artery disease include: Modifiable causes Conditions including obesity, diabetes, high blood pressure, and high cholesterol, which can increase the risk of carotid artery disease Smoking, lack of exercise, and an unhealthy diet Non-modifiable causes Age (women who are over 75 years of age have a greater risk than men in the same age group, and men younger than 75 years of age are more prone to developing carotid artery disease than women in the same age group) Family history of the disease Those who suffer from coronary artery disease (hardening of the arteries supplying blood to the heart) are more prone to developing carotid artery disease