The human arteries contain a thin delicate inner lining called endothelium. A healthy endothelium is necessary to get good erections. Endothelium uses nitric oxide to send signals to surrounding muscles. Upon receiving the signals from endothelium the muscles surrounding the arteries relax and blood rushes into arteries. The same process happens in arteries of penis to cause hard erections. Hence healthy arteries are required for healthy erections.
When the cholesterol level increases in blood, the excess cholesterol gets accumulated on the inner walls of arteries, as hard plaques. This narrows the lumen of arteries. (Diameter of the arteries reduces). Due to reduced diameter, the blood flow through arteries also gets reduced. Increased blood cholesterol also affects the release of nitric oxide. This prevents the relaxation of penile tissues and troubles the process of erection.
Erectile dysfunction may be an early symptom for increased blood cholesterol level. The risk of Erectile dysfunction is nearly two times greater in men with total cholesterol levels above 240 than in men with total cholesterol levels below 180. In men erectile dysfunction may be an early symptom of high cholesterol. Adults should get their blood cholesterol level checked frequently.