Many factors can increase your chances of having heart problems or a stroke if you have high cholesterol. These include: an unhealthy diet – in particular, eating high levels of saturated fat smoking – a chemical called acrolin, found in cigarettes, stops HDL transporting cholesterol from fatty deposits to the liver, leading to narrowing of the arteries (atherosclerosis) having diabetes or high blood pressure (hypertension) having a family history of stroke or heart disease There's also an inherited condition called familial hypercholesterolaemia. This can cause high cholesterol even in someone who eats healthily