What is cholesterol?

Cholesterol is made up of fats in the bloodstream and appears as a waxy-like substance in blood and on the walls of the arteries. Some cholesterol is necessary for the cells of your body to function normally. However, if your cholesterol is high, you may have more deposits on the artery walls, which increases risk of heart disease and stroke by making it more difficult for blood to flow through the walls of the arteries.
Cholesterol is a waxy, fat-like substance found in whole-milk dairy products, eggs, animal fats and meat. It belongs to a family of chemicals called lipids, which also includes fat and triglycerides. It is found in cell walls or membranes throughout the human body and is used to produce hormones, vitamin D and the bile acids that aid the digestion of fat. Your body is able to meet all these needs by producing cholesterol in the liver.

Cholesterol is a type of fat carried in your blood vessels. Your body makes most of the cholesterol you have. The rest comes from the food you eat.

It's normal and healthy to have some cholesterol in your blood. But you don't want too much.

High cholesterol can cause a heart attack or stroke. It can also lead to other serious health problems.

Dr. Michael T. Murray, ND
Naturopathic Medicine Specialist

Cholesterol is a fatty substance in the body that serves several vital roles. It is a building block for various hormones and bile acids; and it plays a major role in stabilizing cell membranes. While proper cholesterol levels are important to good health, the evidence overwhelmingly demonstrates that elevated blood cholesterol levels greatly increase the risk of death due to heart disease.

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Cholesterol is an essential part of the cell membrane and is a necessary precursor to making numerous hormones. You get some cholesterol from the foods you eat, but most of your cholesterol is made in your liver. Saturated fats, and trans fats in particular, drive the production of low-density lipoprotein (LDL), which is referred to as "bad" cholesterol because it promotes the buildup of plaque in your arteries. High-density lipoprotein (HDL) is referred to as "good" cholesterol because it pulls LDL out of circulation, thereby helping to prevent the buildup of plaque.

Cholesterol is an essential fatty substance found in all of the body's cells and transported throughout the body via the bloodstream. It's either produced by the liver or absorbed from the foods you eat. Although too much fat in the blood poses a health risk, your body needs a certain amount of cholesterol to perform several important functions, such as maintaining cellular structures and transmitting nerve impulses.

Dr. Ozgen Dogan
Cardiologist (Heart Specialist)

Cholesterol is a steroid molecule like wax that's found in our blood. It forms the walls of every single cell in our bodies, is necessary for the production of hormones, makes vitamin D and generates bile acids which help us digest fat. Our liver makes 1,500 milligrams (mg) of it a day. Additionally, we get a small amount of cholesterol from what we eat; 150 to 200 mg comes from animal-based foods—meat, eggs, milk, cheese, etc. However, if we exceed that amount by eating too much saturated fat, our bodies respond by making too much cholesterol. When cholesterol becomes "too much of a good thing," it can clog our blood vessels and lead to heart disease.

Cholesterol is a fatty substance used to build cell walls. Cholesterol also has several important functions in making hormones, vitamin D and bile acids. All cells can produce cholesterol but most cholesterol is made in the liver and gut. The liver is the main organ for breaking down cholesterol by converting it to bile acids. If excess cholesterol is produced or eaten, or if the cholesterol is broken down too slowly, there will be excess cholesterol in the blood. Cholesterol may then be deposited in the walls of blood vessels resulting in the onset of atherosclerosis.

Laura Motosko, MSEd, RD
Nutrition & Dietetics Specialist

Cholesterol is a waxy, fat like substance found in the cells of your body. Your body produces all the cholesterol it needs for necessary functions including making hormones, and vitamin D as well as digesting food. A lipoprotein is a small container to carry cholesterol in your bloodstream, made up of fat (lipid) on the inside and protein on the outside. There are two types of lipoprotein including LDL (low density lipoprotein) and HDL (high density lipoprotein). The bad or lousy LDL cholesterol in high amounts in your blood, build up along the arteries which take blood away from your heart to your body and can lead to heart disease. The good or healthy HDL cholesterol transports cholesterol in your body to your liver where it is removed.

Cholesterol is a soft waxy substance. It comes from two sources: your body and the foods that you eat. The cholesterol that travels in your bloodstream is made by the liver and is called blood cholesterol. The cholesterol that comes from foods you eat is called dietary cholesterol. Your body needs cholesterol to produce hormones, vitamin D, and bile acids, which help absorb fat. The body can make all of the cholesterol it needs. If your blood cholesterol is too high, your arteries can become clogged and slow down and block the flow of blood, which could lead to a heart attack or stroke.

Cholesterol is a type of lipid (a fat-soluble molecule) found in three places: in our cells, in our food ("dietary" cholesterol), and in our blood. As much as we fear cholesterol, it is a key and vital component of our bodies. Cholesterol is required for the body to manufacture hormones, build cell walls, and produce bile acids, which are essential for the breakdown and digestion of fats. In some areas of the body, cholesterol levels are normally very high. For example, skin cells contain a lot of cholesterol, making them highly water-resistant. This quality protects the body from dehydration by reducing the evaporation of water. The brain also contains high concentrations of cholesterol. (Low cholesterol becomes a problem if the brain doesn't get enough cholesterol for its normal functioning.)

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Cholesterol is a waxy, fat-like substance used by the body to build cell walls and make certain vitamins and hormones. The liver produces enough cholesterol for the body, but cholesterol also comes from animal products. Eating too much cholesterol, trans-fatty acids, and saturated fats can cause the blood cholesterol to rise and accumulate along the inside walls of blood vessels. This is a risk factor for heart attack and stroke.

Cholesterol is a form of fat that is carried through the body in two kinds of bundles, or lipoproteins. It's important to have healthy levels of both.

Low-density lipoproteins (LDL), or "bad" cholesterol, can lead to a buildup of cholesterol in the arteries. In general, the lower your LDL, the better. Reaching your LDL target is the most effective way to protect your heart and blood vessels.

High-density lipoproteins (HDL), or "good" cholesterol, helps remove cholesterol from your body. In general, the higher your HDL the better.


Dr. David M. Najman, MD
Cardiologist (Heart Specialist)
Cholesterol is a substance found in animal tissues and various foods. It is made by the liver and is important as a constituent of cell membranes and a precursor to steroid hormones. An individual's cholesterol is initially determined genetically, but lifestyle factors such as exercise and diet will effect both the good and the bad cholesterol levels.
Eric Olsen
Fitness Specialist
Cholesterol is a waxy substance called a sterol. It is not a type of fat. It's found only in foods that come from animal sources, but our own livers also manufacture cholesterol as an essential component of a well-functioning metabolism. Cholesterol is a precursor to several essential hormones, including sex hormones and adrenaline (interestingly, and perhaps not surprisingly, research with rats notes that those rats on severe low-cholesterol diets have very bad tempers, and any human who has also spent time on a low-cholesterol diet can probably sympathize).
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Cholesterol is a type of blood lipid. It has a number of subfractions. High density lipoprotein cholesterol (sometimes called HDL, or “good” cholesterol) protects against atherosclerosis, while low-density lipoprotein cholesterol (LDL, or “bad” cholesterol) leads to the development of atherosclerosis. As the body tries to eliminate cholesterol, it becomes oxidized and is taken up by macrophages (scavenger cells) that, in an attempt to remove the cholesterol from the blood, move it into the walls of arteries, creating atherosclerotic plaques (or coronary disease). The more cholesterol and active macrophages in an artery, the more unstable it becomes; and the more unstable the plaque in an artery, the greater the likelihood of a heart attack.

Cholesterol is a fatty substance present in all parts of the body. It is a component of cell membranes and is used to make vitamin D and some hormones. Some cholesterol in the body is produced by the liver and some is derived from food, particularly animal products. A high level of cholesterol in the blood can help cause atherosclerosis and coronary artery disease. In the blood, cholesterol is bound to chemicals called lipoproteins. Cholesterol attached to low-density lipoprotein (LDL) harms health and is often called "bad cholesterol." Cholesterol attached to high-density lipoprotein (HDL) is good for health and is often called "good cholesterol."

This answer is based on source information from National Women's Health Information Center.

Cholesterol is a waxy, or fat-like, substance that can build up in your arteries and lead to cardiovascular disease. You might think of cholesterol as all bad, but your body actually needs a small amount of cholesterol and is able to produce it naturally. Cholesterol maintains the health of the outer wall of cells, called the membrane, and aids in production of bile acids, hormones and some vitamins (including vitamin D). High levels of low-density lipoprotein (LDL) cholesterol are what concern physicians most. These high levels of LDL, or “bad,” cholesterol are a result of eating foods from animal sources (some meats and types of seafood, dairy) or can be caused by genetic factors. A build-up of LDL cholesterol in the arteries can cause narrowing and blockages and prevent blood flow, leading to heart attacks, strokes and other serious illnesses.

Cholesterol is a waxy substance that is both produced by the body and found in certain foods, especially meat and dairy products. When cholesterol levels in the blood are abnormally high, it can accumulate inside blood vessels, narrowing the channels through which blood flows. High cholesterol is linked to coronary artery disease, peripheral vascular disease (PVD), stroke, and high blood pressure.

Cholesterol, a waxy, fat-like compound, belongs to a class of molecules called steroids. Cholesterol is found in many foods, in the bloodstream and in all the body's cells. If you would fill your hand with cholesterol, it might feel like a soft, melted candle.

Despite the problems with certain cholesterols, it is essential for:

  • The formation and maintenance of cell membranes
  • The formation of sex hormones (progesterone, testosterone, estradiol, cortisol)
  • The production of bile salts, which help to digest food
  • The conversion into vitamin D when the skin is exposed to sunlight.

Forming cholesterol involves a series of complicated biochemical reaction. Cholesterol is made primarily in your liver (approximately 1,000 milligrams a day). It is also created by cells lining the small intestine as well as by other individual cells in the body.

Dr. Mimi Guarneri
Cardiologist (Heart Specialist)

Cholesterol is a steroid found in cell membranes of all animals and circulates in the blood. It is also an important molecule used by the body to create bile, hormones, and several fat‐soluble vitamins such as Vitamins A, D, and E. Cholesterol comes from 2 sources; diet and liver production. The liver converts cholesterol into bile, useful for the digestion of dietary fats.

Dietary sources of cholesterol include animal fat (such as beef, chicken, and poultry), cheese, egg yolk, nuts and milk. Synthesis of cholesterol in the liver decreases if cholesterol intake from diet is high. To lower cholesterol from dietary intake, people should limit (as much as possible) saturated and trans fats. Saturated fats are found in non‐fat‐free dairy products. Trans fats are a result of what is called partial hydrogenation of saturated fats which is found in snack foods, fast foods, margarine, fried/baked foods, etc. Trans fats are not found naturally occurring and cannot be digested and utilized and are a major contributor to the development of atherosclerosis. Reading food labels and looking for words like "partially hydrogenated" can help you determine the occurrence of trans fats.

Dr. Andrea Pennington, MD
Integrative Medicine Specialist
Cholesterol is a soft, waxy substance found among the lipids (fats) in the bloodstream and in your body's cells. There are different types of cholesterol: HDL (good form) and LDL (bad form).

Cholesterol is a fatty/waxy type substance, which is found in the blood. It is needed for normal function of the body, but can be harmful if excess amounts are present in the blood.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.