Cholesterol: What It Is, What Raises It, and How to Lower It

Cholesterol is a waxy, fat-like substance found in all the body's cells. The body needs some to make hormones, vitamin D and substances that help digest food — and it makes all it needs. Cholesterol is also in foods from animals, such as egg yolks, meat and cheese.

Too much cholesterol in the blood can combine with other substances to form plaque, which sticks to artery walls. This buildup, atherosclerosis, can lead to coronary artery disease, in which the heart's arteries narrow or even close.

HDL, LDL and VLDL

These are lipoproteins — combinations of fat (lipid) and protein that let fats travel in the blood.

What causes high cholesterol

The most common cause is an unhealthy lifestyle:

• eating habits, such as a lot of saturated fat — in red meat, full-fat dairy, chocolate, some baked goods and many deep-fried and processed foods — which raises LDL;
• inactivity, lots of sitting and little exercise, which lowers HDL;
• smoking, which lowers HDL (especially in women) and raises LDL;
• stress, which may raise hormones such as corticosteroids that make the body produce more cholesterol;
• too much alcohol, which can raise total cholesterol.

Genetics matter too — familial hypercholesterolemia (FH) is inherited and causes very high cholesterol — and so can other conditions and some medicines.

Risk factors

• Age: levels tend to rise over time, though children and teens can have high cholesterol too.
• Sex: from 20 to 39, men are at greater risk of high total cholesterol; after menopause, women's risk rises, as protective female hormones fall.
• Family history.
• Other conditions: diabetes, chronic kidney disease, HIV and lupus.
• Medicines: steroids, some chemotherapy, medicines taken after an organ transplant, some heart medicines and certain acne medicines.
• Race or ethnicity: for example, Asian Americans are more likely to have high LDL, and non-Hispanic White people high total cholesterol.
• Weight: overweight or obesity raises cholesterol.

What it can lead to

If plaque ruptures, a blood clot can form on it and block a coronary artery; less oxygen-rich blood to the heart causes angina (chest pain) or a heart attack. Plaque in arteries to the brain and limbs can cause carotid artery disease, stroke and peripheral arterial disease.

Testing

High cholesterol usually has no symptoms — a blood test finds it. How often depends on age, risk factors and family history:

Lowering it

• Heart-healthy lifestyle changes: a heart-healthy eating plan, weight management and regular physical activity.
• Medicines, such as statins, if lifestyle changes aren't enough — while keeping up those changes.
• Lipoprotein apheresis for some people with FH: a machine filters LDL out of the blood and returns the rest.

Sources

Based on "Cholesterol," MedlinePlus, National Library of Medicine, with its summary from the National Heart, Lung, and Blood Institute; a work of the United States government in the public domain.