Hyperlipidemia is a condition in which cholesterol and triglycerides, types of fat (lipids) in your blood, are abnormally elevated. Over time, excess lipids deposit in artery walls, forming plaques that narrow blood vessels and reduce blood flow to the heart, brain, and other organs. This process, called atherosclerosis, is a leading cause of heart attack, stroke, and peripheral artery disease.
Cholesterol is a waxy substance your liver produces, and you also get it from food. Your body needs it to make hormones, vitamin D, and cell membranes, but elevated levels raise cardiovascular risk. Triglycerides are another blood fat, made largely from carbohydrates and alcohol, and high levels also promote atherosclerosis.
Most importantly, hyperlipidemia produces no symptoms, and blood vessels narrow silently over years or decades. This is precisely why it’s called the “silent killer” and why routine screening is so critical.
What is high cholesterol?
High cholesterol refers to elevated total or LDL cholesterol, the form that deposits in artery walls, and it’s the primary target of treatment. Cholesterol travels in several forms: total cholesterol (the sum of all types), LDL (the “bad” cholesterol that builds up in arteries), HDL (the “good” cholesterol that clears LDL away), and non-HDL cholesterol (a secondary target). High cholesterol can be primary (genetic) or secondary (driven by diet, lifestyle, or other diseases), and most cases are secondary and respond to lifestyle change.
What are triglycerides?
Triglycerides are the most common fat in the blood, drawn from food (especially carbohydrates and alcohol) and produced by the liver. Some are necessary for energy, but elevated levels raise the risk of heart disease, stroke, and, when extremely high (above 1,000 mg/dL), pancreatitis. High triglycerides often pair with low HDL and obesity as part of metabolic syndrome, a cluster of conditions that sharply raises cardiovascular risk.
Related terms and distinctions
The terms hyperlipidemia and dyslipidemia are often used interchangeably, though dyslipidemia is broader, covering any abnormal lipid pattern (high total cholesterol, high LDL, low HDL, high triglycerides, or combinations).
Hypercholesterolemia refers specifically to elevated cholesterol, and familial hypercholesterolemia is a rare inherited form causing very high cholesterol from birth.
Familial chylomicronemia (Type I hyperlipidemia) is a separate genetic disorder of triglyceride metabolism, while most people with high triglycerides have secondary patterns driven by diet, weight, or metabolic disease.