Dyslipidemia (high cholesterol and triglycerides)

Dyslipidemia means that your lipids, the fats that travel in your blood, are at abnormal levels. The main ones are LDL cholesterol, HDL cholesterol, and triglycerides, which are another kind of fat. The tricky part is that you usually can't feel it: it typically causes no symptoms and is picked up on a blood test.

The real story plays out in the arteries. LDL and HDL are lipoproteins, tiny particles that carry fat through the bloodstream in a neat package. When there's too much LDL and too many lipoproteins loaded with triglycerides, they tend to get stuck in the artery wall. There they can set off inflammation, a defensive reaction that irritates the wall, and that inflammation drives atherosclerosis: fatty plaques that build up in the artery wall. Think of the scale that builds up inside a pipe so less water can get through; in an artery, those plaques can let less blood through.

That's why dyslipidemia can raise the risk of cardiovascular disease, meaning disease of the heart and blood vessels. Examples include coronary artery disease, which affects the arteries that supply the heart with blood; peripheral artery disease, which affects arteries farther from the heart, such as those in the legs; and stroke, which happens when the blood supply to the brain is cut off.