When is cholesterol bad?Nonetheless, a high blood cholesterol level, especially elevated low-density lipoproteins (LDL), is considered a contributor to plaque build up in the arteries and impeded blood flow to the brain, kidneys, genitals, extremities, and heart. It is among the primary causes of heart disease, because cholesterol produces deposits in arteries. High cholesterol levels may also be implicated in gallstones, erectile dysfunction (although it is often the drugs prescribed to deal with high cholesterol that cause this), mental impairment, and high blood pressure.