High cholesterol and high blood pressure are two entirely different conditions, with possibly the only common factors being the detrimental effect they have on the cardiovascular system and the cause lying at least partly in the person's diet. However, apart from this, the conditions differ greatly - the basic causes and the mechanism of the condition, the symptoms, the effects that they have on the body, and the treatment required.
The condition in which cholesterol levels in the blood are excessively high is known as hypercholesterolemia, and it primarily affects the cardiovascular system, causing angina, stroke, heart attacks, and other complications. When blood pressure goes beyond a healthy limit, the condition is known as hypertension. Hypertension can cause a number of problems, including strokes and heart attacks, as well as damage to other organs, such as the kidneys and the retina. When hypertension is discovered, doctors commonly check for high cholesterol too, but this is not because of any link, rather because the added complication of high cholesterol makes the situation more risky. As for whether they can kill you - yes, as you can see from the list of effects of these conditions, they can be fatal. You should therefore not delay beginning treatment and making some lifestyle changes.
answered by M W