Dyslipidemia

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Dyslipidemia is a high level of lipids (cholesterol, triglycerides, or both) or a low high-density lipoprotein (HDL) cholesterol level.

Lifestyle, genetics, disorders (such as low thyroid hormone levels or kidney disease), drugs, or a combination can contribute.
Atherosclerosis can result, causing angina, heart attacks, strokes, and peripheral arterial disease.
Doctors measure levels of triglycerides and the various types of cholesterol in blood.
Exercise, dietary changes, and drugs can be effective.

(See also Overview of Cholesterol and Lipid Disorders.)
Important fats (lipids) in the blood are

Cholesterol
Triglycerides

Cholesterol is an essential component of cell membranes, of brain and nerve cells, and of bile, which helps the body absorb fats and fat-soluble vitamins. The body uses cholesterol to make vitamin D and various hormones, such as estrogen , testosterone , and cortisol . The body can produce all the cholesterol that it needs, but it also obtains cholesterol from food.
Triglycerides, which are contained in fat cells, can be broken down, then used to provide energy for the body’s metabolic processes, including growth. Triglycerides are produced in the intestine and liver from smaller fats called fatty acids. Some types of fatty acids are made by the body, but others must be obtained from food.
Lipoproteins are particles of proteins and other substances. They carry fats, such as cholesterol and triglycerides, which cannot circulate freely in the blood by themselves.
There are different types of lipoproteins (see table Lipoproteins: Lipid Carriers), including

Chylomicrons
Very low density lipoproteins (VLDL)
Low-density lipoproteins (LDL)
High-density lipoproteins (HDL)

Levels of lipoproteins and therefore lipids, particularly low-density lipoprotein (LDL) cholesterol, increase slightly as people age. Levels are normally slightly higher in men than in women, but levels increase in women after menopause. The increase in levels of lipoproteins that occurs with age can result in dyslipidemia.
The risk of developing atherosclerosis increases as the total cholesterol level (which includes LDL, HDL, and VLDL cholesterol) increases, even if the level is not high enough to be considered dyslipidemia. Atherosclerosis can affect the arteries that supply blood to the heart (causing coronary artery disease), those that supply blood to the brain (causing stroke), and those that supply the rest of the body (causing peripheral arterial disease). Therefore, having a high total cholesterol level also increases the risk of having a heart attack or stroke.
Having a low total cholesterol level is generally considered better than having a high one. However, having a very low cholesterol level may not be healthy either (hypolipidemia).
Although there is no natural cutoff between normal and abnormal cholesterol levels, for adults, a total cholesterol level of less than 200 milligrams per deciliter of blood (mg/dL [