High Cholesterol: Types Make an Appointment Refer a Patient Ask a Question Reviewed by Howard D. Weinberger, MD, FACC (July 01, 2019) Types of Cholesterol and Lipoproteins The types of cholesterol and lipoproteins include: Low-Density Lipoprotein (LDL) or Bad Cholesterol — Plaque Builder When too much LDL circulates in the blood, it can slowly build up in the inner walls of the arteries that feed blood to the body. Together with other substances, it can form plaque (or atheroma). Plaque is a thick, hard deposit that can narrow the arteries, make them less flexible and limit the amount of blood they can deliver. This condition is known as atherosclerosis. As the artery narrows and hardens, less blood can get through, causing ischemia, or a lack of necessary nutrients. If a clot or blockage forms in a narrowed artery to the heart or the brain, a heart attack or stroke can result. High-Density Lipoprotein (HDL) or Good Cholesterol — The Bad Cholesterol Eater About one-fourth to one-third of blood cholesterol is carried by HDL. HDL cholesterol is known as "good" cholesterol, because high levels of HDL seem to protect against heart attack. Low levels of HDL (less than 40 mg/dL) also increase the risk of plaque buildup and heart disease. HDL tends to carry cholesterol away from the arteries and back to the liver, where it's passed from the body — in a way, it "eats" up the bad cholesterol. Some experts believe that HDL removes excess cholesterol from arterial plaque, slowing its buildup. Triglycerides — Blood Fats Triglyceride is a form of fat made in the body. Elevated triglycerides can be due to being overweight or obese, diabetes, physical inactivity, cigarette smoking, excess alcohol consumption or a diet very high in carbohydrates (60 percent of total calories or more). People with high triglycerides often have a high total cholesterol level, including a high LDL (bad) level and a low HDL (good) level. Many people with heart disease and/or diabetes also have high triglyceride levels. Lp(a) Cholesterol Lp(a) is a genetic variation of LDL (bad) cholesterol. A high level of Lp(a) is a significant risk factor for the premature development of fatty deposits in arteries. Lp(a) isn't fully understood, but it may interact with substances found in artery walls and contribute to the buildup of fatty deposits. High Cholesterol: Causes Clinical Trials For more than 100 years, National Jewish Health has been committed to finding new treatments and cures for diseases. Search our clinical trials.