There are many types of cholesterol. The ones talked about most are:
Total cholesterol - all the cholesterols combined
High density lipoprotein (HDL) cholesterol - often called "good" cholesterol
Low density lipoprotein (LDL) cholesterol - often called "bad" cholesterol
For many people, abnormal cholesterol levels are partly due to an unhealthy lifestyle. This often includes eating a diet that is high in fat. Other lifestyle factors are:
Lack of exercise
Some health conditions can also lead to abnormal cholesterol, including:
Polycystic ovary syndrome
Pregnancy and other conditions that increase levels of female hormones
Underactive thyroid gland
Medicines such as certain birth control pills, diuretics (water pills), beta-blockers, and some medicines used to treat depression may also raise cholesterol levels. Several disorders that are passed down through families lead to abnormal cholesterol and triglyceride levels. They include:
Familial combined hyperlipidemia
Smoking does not cause higher cholesterol levels, but it can reduce your HDL ("good") cholesterol.
Exams and Tests
A cholesterol test is done to diagnose a lipid disorder. Some guidelines recommend having your first screening cholesterol test at age 20. Everyone should have their first screening test by age 35 in men, and age 45 in women. (Note: Different experts recommend different starting ages.)
It is important to work with your health care provider to set your cholesterol goals. General targets are:
LDL: 70-130 mg/dL (lower numbers are better)
HDL: more than 50 mg/dL (high numbers are better)
Total cholesterol: less than 200 mg/dL (lower numbers are better)
Triglycerides: 10-150 mg/dL (lower numbers are better)
If your cholesterol results are abnormal, your doctor may also do:
Blood sugar (glucose) test to look for diabetes
Kidney function tests
Thyroid function tests to look for an underactive thyroid gland
Steps you can take to improve their cholesterol levels, and help prevent heart disease and a heart attack include:
Quit smoking. This is the single biggest change you can make to reduce your risk of heart attack and stroke.Eat foods that are naturally low in fat. These include whole grains, fruits, and vegetables.
Use low-fat toppings, sauces, and dressings.
Avoid foods that are high in saturated fat.
Lose weight if you are overweight
Your doctor may want you to take medicine for your cholesterol if lifestyle changes do not work. This will depend on:
Whether or not you have heart disease, diabetes, or other blood flow problems
If you have heart disease or diabetes, your LDL cholesterol should stay below 100 mg/dL
If you are at risk for heart disease (even if you do not yet have any heart problems), your LDL cholesterol should be below 130 mg/dL
Almost everyone else may get health benefits from LDL cholesterol that is lower than 160 mg/dL to 190 mg/dL
There are several types of drugs to help lower blood cholesterol levels. The drugs work in different ways. Statins are one kind of drug that lower cholesterol and are the most effective at reducing the chance of heart disease.
High cholesterol levels can lead to hardening of the arteries, also called atherosclerosis. This occurs when fat, cholesterol, and other substances build up in the walls of arteries and form hard structures called plaques.
Over time, these plaques can block the arteries and cause heart disease, stroke, and other symptoms or problems throughout the body.
Disorders that are passed down through families often lead to higher cholesterol levels that are harder to control.
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Genest J, Libby P. Lipoprotein disorders and cardiovascular disease. In: Bonow RO, Mann DL, Zipes DP, Libby P, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 9th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 47.
U.S. Preventive Services Task Force. Screening for lipid disorders in adults: U.S. Preventive Services Task Force recommendation statement. Rockville (MD): Agency for Healthcare Research and Quality (AHRQ);2008 Jun.
U.S. Preventive Services Task Force. Screening for lipid disorders in children. U.S. Preventive Services Task Force recommendation statement. Rockville (MD): Agency for Healthcare Research and Quality (AHRQ);2007 Jul.
David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.