High cholesterol risk factors: what raises LDL, and how to lower it

The most common cause

The National Heart, Lung, and Blood Institute (NHLBI) says an unhealthy lifestyle is the most common cause of high "bad" LDL cholesterol or low "good" HDL cholesterol. Genes you inherit from your parents, other medical conditions and some medicines can also raise LDL or lower HDL (NHLBI causes).

Lifestyle habits that raise the risk

The NHLBI lists these habits (NHLBI causes):

• Saturated fat: eating a lot of foods high in saturated fats raises LDL cholesterol. Saturated fats are found in fatty cuts of red meat and dairy products. No more than 10% of your daily calories should come from them.
• Little physical activity: lack of activity is linked to a higher risk of unhealthy cholesterol levels.
• Smoking: lowers HDL cholesterol, particularly in women, and raises LDL cholesterol.
• Stress: may raise levels of certain hormones, such as corticosteroids, which can cause your body to make more cholesterol.
• Too much alcohol: more than two drinks a day for men or one drink a day for women can raise your total cholesterol.
• Poor sleep: getting little or low-quality sleep has been linked to lower cardiovascular health.

MedlinePlus names an unhealthy lifestyle as the most common cause: eating a lot of saturated fat, sitting a lot with little exercise, smoking, stress and drinking too much alcohol. It adds that overweight or obesity raises cholesterol (MedlinePlus).

Risk factors you cannot change

• Family history: family members usually have similar cholesterol levels. Changes in the genes that control cholesterol can be passed from parent to child and cause familial hypercholesterolemia, which makes it harder for your body to remove LDL from your blood (NHLBI causes). MedlinePlus notes that FH is inherited and causes very high cholesterol levels in the blood (MedlinePlus).
• Age: unhealthy cholesterol can affect people of all ages, even young children, but high cholesterol is most commonly diagnosed between ages 40 and 59. As you get older, your liver does not remove LDL cholesterol as well as it did (NHLBI causes).
• Sex: between ages 20 and 39, men have a greater risk of high total cholesterol than women. A woman's risk goes up after menopause, when total and LDL cholesterol usually go up and HDL goes down (NHLBI causes).
• Race or ethnicity: the NHLBI says non-Hispanic White people overall are more likely to have high total cholesterol, and Asian Americans, including those of Indian, Filipino, Japanese and Vietnamese descent, are more likely to have high LDL than other groups (NHLBI causes). More on HDL differences in the HDL cholesterol guide.

Health conditions and medicines

The NHLBI says to talk to your healthcare provider about your risk of high cholesterol if you have chronic kidney disease, diabetes, HIV/AIDS, hypothyroidism, lupus, overweight or obesity, polycystic ovary syndrome (PCOS) or sleep apnea (NHLBI causes).

Some medicines taken for other health problems can raise LDL or lower HDL. The NHLBI names arrhythmia medicines such as amiodarone, beta-blockers, some chemotherapy medicines, diuretics such as thiazide, immunosuppressive medicines such as cyclosporine, retinoids for acne, and steroids such as prednisone (NHLBI causes). MedlinePlus also names medicines taken after an organ transplant (MedlinePlus). Do not stop a prescribed medicine on your own; ask your provider.

Why you may not know you have it

High LDL cholesterol usually does not cause symptoms. Most people do not know they have high cholesterol until they have a blood test during a routine visit (NHLBI symptoms). If levels are very high, mostly in people with familial hypercholesterolemia, signs can include fatty bumps on the skin (xanthomas), especially on the elbows, knees, hands or ankles, and grayish-white rings around the cornea of the eye (NHLBI symptoms).

Undiagnosed or untreated high cholesterol can lead to serious problems, such as heart attack and stroke (NHLBI symptoms). MedlinePlus explains that cholesterol can build up as plaque in the arteries, and an area of plaque can break open so a clot forms that can block blood flow (MedlinePlus).

How and when it is checked

A blood test called a lipid panel measures total cholesterol, LDL, HDL and triglycerides. Your provider may ask you to fast for 8 to 12 hours first (NHLBI diagnosis). For healthy people, the NHLBI gives this general guide (NHLBI diagnosis):

• Ages 19 or younger: screening begins at ages 9 to 11 and is repeated every 5 years; it may be done as early as age 2 if there is a family history of high cholesterol, heart attack or stroke. See the child cholesterol screening check.
• Ages 20 to 65: younger adults every 5 years; men ages 45 to 65 and women ages 55 to 65 every 1 to 2 years.
• Older than 65: every year.

The NHLBI says the goal for a healthy lipid profile is non-HDL cholesterol below 130 mg/dL, with HDL of at least 40 mg/dL for men and 50 mg/dL for women, and to check with your provider on the levels that are best for you (NHLBI diagnosis). MedlinePlus lists a healthy total cholesterol for adults age 20 or older as less than 200 mg/dL (MedlinePlus), and healthy triglycerides in adults as less than 150 mg/dL (MedlinePlus). What the numbers mean by age is in cholesterol levels by age; work out LDL from a panel with the LDL calculator, and read about triglycerides.

A lipoprotein(a), or Lp(a), test is not usually part of a routine panel. Your Lp(a) level is set by your genes, and your provider may order it if you have a family history of stroke or early heart disease, or do not know your family history (NHLBI diagnosis).

Steps that may lower it

The NHLBI says your provider may talk to you about these changes to lower LDL (NHLBI treatment):

• Heart-healthy foods: limit saturated fats in fatty meats, dairy and desserts; eat whole grains, fruits and vegetables rather than sweets; eat a variety of nuts; use little or no salt.
• Regular physical activity: can lower LDL and triglycerides and raise HDL. Ask your provider what level is right for you first.
• A healthy weight: adults with overweight and obesity can lower LDL and raise HDL by losing only 3% to 5% of their weight.
• Managing stress, quitting smoking and limiting alcohol. For free help to quit, the National Cancer Institute's quitline is 1-877-44U-QUIT (1-877-448-7848).
• Enough sleep: 7 to 9 hours of sleep a day lowers your risk of high LDL and total cholesterol.

If lifestyle changes are not enough, your provider may prescribe medicine; statins are the most common (NHLBI treatment). MedlinePlus adds that if you take medicine, you should keep up the lifestyle changes too (MedlinePlus). The statin eligibility check shows what the US Preventive Services Task Force advises, and heart disease risk factors puts cholesterol next to the other risks.

Common questions

What is the main cause of high cholesterol?

The NHLBI says an unhealthy lifestyle is the most common cause, with genes, other conditions and some medicines also playing a part (NHLBI causes).

Can thin, active people have high cholesterol?

Yes. Family history and genes can raise cholesterol, and familial hypercholesterolemia makes it harder for the body to clear LDL (NHLBI causes). Most people only find out from a blood test (NHLBI symptoms).

Does high cholesterol cause symptoms?

Usually not. Signs such as xanthomas appear mostly when levels are very high in inherited cases (NHLBI symptoms).

Can high cholesterol be prevented?

The NHLBI says that even with a family history, a heart-healthy lifestyle can help prevent unhealthy cholesterol levels, and heart-healthy habits can start in childhood and continue throughout life (NHLBI causes).