Dyslipidemia

What dyslipidemia means

Lipids are fats in the blood carried by particles called lipoproteins. The main measurements are:

• LDL cholesterol: carries cholesterol into artery walls; the main driver of plaque
• HDL cholesterol: helps remove cholesterol from the body; low levels are linked to higher risk
• Triglycerides: fats from food and the liver, used for energy
• Non-HDL cholesterol: total cholesterol minus HDL, capturing all plaque-forming particles
• Lipoprotein(a): an inherited particle that raises heart risk; tested at least once in adulthood in many guidelines

Dyslipidemia vs hyperlipidemia: hyperlipidemia means high lipids. Dyslipidemia is broader and includes low HDL, which is not "hyper". Mixed dyslipidemia means high LDL and high triglycerides together, often with low HDL.

Cholesterol levels: what is normal

For adults, in mg/dL (mmol/L):

People with heart disease or diabetes usually have lower LDL targets, often below 70 mg/dL (1.8 mmol/L) or even 55 mg/dL in very high-risk people.

Causes and risk factors

Lifestyle

• diets high in saturated and trans fats, refined starches and sugar
• excess weight, especially around the waist
• physical inactivity
• smoking, which lowers HDL
• heavy alcohol use, which raises triglycerides

Medical conditions (secondary dyslipidemia)

• Type 2 diabetes and insulin resistance, typically causing high triglycerides and low HDL
• Metabolic syndrome
• Hypothyroidism: raises LDL; always checked
• Kidney disease, including nephrotic syndrome
• Liver disease with blocked bile flow
• Pregnancy, in which lipids normally rise
• Medicines: steroids, some HIV drugs, retinoids, some diuretics and beta-blockers, oral estrogen, some antipsychotics, immunosuppressants

Genetic (primary) dyslipidemia

• Familial hypercholesterolemia: affects about 1 in 250 people; LDL is very high from birth, causing heart attacks as early as the 30s or 40s if untreated
• Familial combined hyperlipidemia and inherited high triglyceride disorders
• High lipoprotein(a)

Symptoms

Dyslipidemia is usually silent. Clues may include:

• Xanthelasma: yellow fatty patches on the eyelids
• Tendon xanthomas: lumps on the Achilles or knuckle tendons, typical of familial hypercholesterolemia
• Corneal arcus: a gray-white ring around the cornea before age 45
• Eruptive xanthomas: crops of small yellow bumps with very high triglycerides
• Pancreatitis: severe belly pain with triglycerides usually above 1,000 mg/dL

More often, the first sign is a complication such as angina, heart attack or stroke.

Complications

• coronary artery disease and heart attack
• stroke
• peripheral artery disease
• acute pancreatitis from very high triglycerides
• fatty liver disease

Diagnosis

A lipid panel blood test measures total cholesterol, LDL, HDL and triglycerides. Fasting is not usually required, but may be repeated fasting if triglycerides are high. US guidelines suggest checking adults every 4 to 6 years, starting around age 20, and children once between ages 9 and 11, earlier if there is a family history.

Doctors then estimate your 10-year risk of heart attack and stroke using age, sex, blood pressure, diabetes, smoking and cholesterol. Risk enhancers, such as family history, lipoprotein(a), chronic kidney disease and inflammatory diseases, and sometimes a coronary artery calcium scan, help decide on treatment. Blood tests for thyroid, liver, kidney function and blood sugar look for secondary causes.

Treatment

Lifestyle changes for everyone

• Eat a heart-healthy pattern: vegetables, fruit, whole grains, legumes, nuts, fish and olive oil, as in the Mediterranean or DASH diets
• Limit saturated fat (fatty meats, butter, full-fat dairy) and avoid trans fats
• Add soluble fiber: oats, beans, psyllium
• Cut sugar, refined starch and alcohol to lower triglycerides
• Exercise at least 150 minutes a week
• Lose 5 to 10 percent of body weight if overweight
• Stop smoking to raise HDL and reduce heart risk

Medicines

• Statins (atorvastatin, rosuvastatin and others) are first-line. US guidelines recommend them for people with heart or blood vessel disease, LDL of 190 mg/dL or higher, diabetes aged 40 to 75, and others with a 10-year risk of about 7.5 percent or more after discussion
• Ezetimibe reduces cholesterol absorption and is added if targets are not met
• PCSK9 inhibitors (injections) and inclisiran lower LDL dramatically for high-risk people and familial hypercholesterolemia
• Bempedoic acid for people who cannot take statins
• Icosapent ethyl (purified fish oil) for some people with high triglycerides and heart disease or diabetes
• Fibrates for very high triglycerides to prevent pancreatitis

Statins are safe for most people. Muscle aches are the most common complaint; many people can continue with a dose change or a different statin. Report severe muscle pain or dark urine promptly.

Frequently asked questions

What is dyslipidemia?

Dyslipidemia is an abnormal level of blood fats: high LDL cholesterol, high triglycerides, low HDL cholesterol, or a combination. It usually causes no symptoms but increases the risk of heart attack, stroke and, with very high triglycerides, pancreatitis.

What is the difference between dyslipidemia and hyperlipidemia?

Hyperlipidemia means high levels of cholesterol or triglycerides. Dyslipidemia is a broader term that also includes low HDL cholesterol and other unhealthy patterns. In practice, the terms are often used interchangeably.

What causes dyslipidemia?

Common causes are a diet high in saturated fat and refined carbohydrates, excess weight, inactivity, smoking, type 2 diabetes, an underactive thyroid, kidney disease and some medicines. Inherited conditions such as familial hypercholesterolemia cause very high levels from childhood.

Can dyslipidemia be reversed without medication?

Lifestyle changes can lower LDL by roughly 10 to 20 percent and triglycerides even more, which may be enough for people at lower risk. People with very high LDL, inherited conditions, diabetes or heart disease usually also need medicine to reach safe levels.

What are normal cholesterol levels?

For most adults, desirable levels are total cholesterol under 200 mg/dL, LDL under 100 mg/dL, HDL of 40 mg/dL or more for men and 50 or more for women, and triglycerides under 150 mg/dL. Targets are lower for people with heart disease or diabetes.