High cholesterol leads to premature blockages in the heart arteries, heart attacks and strokes. But how do you know if you have high cholesterol? What are the symptoms? The answer is that the majority of people have no symptoms at all until they have a heart attack or a stroke! High cholesterol works in the background causing atherosclerosis, slowly furring up the arteries all over the body. The only way to know if you have it is to get a blood cholesterol check by your doctor.