High CholesterolCauses, Risks, and When to Worry

High cholesterol affects nearly 94 million American adults, yet most don't know they have it. This silent condition develops over years without symptoms, quietly depositing fatty plaques in arteries while you feel perfectly fine. By the time warning signs appear—often a heart attack or stroke—significant damage has already occurred. Understanding what causes high cholesterol and recognizing your risk factors empowers you to take action before problems develop.

The term "high cholesterol" typically refers to elevated LDL cholesterol, though high total cholesterol and triglycerides also matter. What constitutes "high" depends partly on your other cardiovascular risk factors, as someone with diabetes or existing heart disease faces greater danger from the same cholesterol level that might be acceptable in a healthy young adult.

What Is Considered High Cholesterol?

Measurement	Borderline High	High	Very High
Total Cholesterol	200-239 mg/dL	240+ mg/dL	—
LDL Cholesterol	130-159 mg/dL	160-189 mg/dL	190+ mg/dL
Triglycerides	150-199 mg/dL	200-499 mg/dL	500+ mg/dL

These thresholds apply to the general population, but your doctor may set stricter targets based on your individual risk profile. Someone with established heart disease might need LDL below 70 mg/dL, making even "normal" levels of 100 mg/dL too high for them.

What Causes High Cholesterol?

High cholesterol results from a combination of genetic predisposition and lifestyle factors. Understanding these causes helps identify which ones you can modify.

Dietary Factors

Diet significantly influences cholesterol levels, though perhaps not in the ways many people assume. Saturated fat, found abundantly in red meat, full-fat dairy, and tropical oils, raises LDL cholesterol more than any other dietary component. Trans fats, found in some processed foods, are even worse—they raise LDL while simultaneously lowering protective HDL. Dietary cholesterol from foods like egg yolks has less impact than once believed, though it still contributes in some people.

Obesity and Body Weight

Excess weight, particularly abdominal fat, triggers metabolic changes that raise LDL and triglycerides while lowering HDL. The relationship works both ways: losing weight improves cholesterol, while gaining weight worsens it. Even modest weight loss of 5-10% can meaningfully improve your lipid profile.

Physical Inactivity

Sedentary lifestyles contribute to weight gain and unfavorable cholesterol levels. Regular physical activity helps raise HDL, may lower LDL slightly, and improves triglyceride levels. Exercise also helps your body process fats more efficiently.

Genetics

Your genes strongly influence how your body produces and processes cholesterol. Some people maintain low cholesterol despite poor diets, while others have high cholesterol regardless of healthy habits. Familial hypercholesterolemia, a genetic condition affecting about 1 in 250 people, causes very high LDL from birth and dramatically increases heart disease risk without treatment.

Age and Sex

Cholesterol levels tend to rise with age. Before menopause, women typically have lower LDL than men. After menopause, women's LDL often rises to match or exceed men's levels, partly explaining why heart disease risk increases for women later in life.

Medical Conditions

Several health conditions can raise cholesterol levels. Diabetes and insulin resistance worsen the entire lipid profile. Hypothyroidism (underactive thyroid) slows cholesterol clearance from the blood. Kidney disease and liver disease can also affect cholesterol metabolism. Treating these underlying conditions often improves cholesterol levels.

Medications

Some medications raise cholesterol as a side effect. Certain blood pressure drugs, particularly thiazide diuretics and older beta-blockers, can worsen lipid profiles. Corticosteroids, some immunosuppressants, and certain HIV medications may also affect cholesterol. If you suspect medication is affecting your cholesterol, discuss alternatives with your doctor rather than stopping treatment on your own.

Does High Cholesterol Cause Symptoms?

High cholesterol itself causes no symptoms. You cannot feel cholesterol building up in your arteries. This is why it's often called a "silent" condition and why regular testing is so important.

The damage from high cholesterol accumulates over years and decades. Symptoms appear only when complications develop:

• Chest pain (angina): When coronary arteries become significantly blocked, reduced blood flow to the heart causes chest pain, especially during exertion.
• Heart attack: If a plaque ruptures and blocks a coronary artery completely, heart muscle begins to die. Warning signs include severe chest pressure, shortness of breath, and pain radiating to the arm, jaw, or back.
• Stroke: Blocked arteries in the brain or clots that travel from elsewhere can cause sudden numbness, confusion, trouble speaking, vision changes, or severe headache.
• Peripheral artery disease: Plaque in leg arteries causes pain when walking, slow-healing wounds, and in severe cases, tissue death requiring amputation.

In rare cases of extremely high cholesterol, visible signs may appear. Xanthomas are yellowish cholesterol deposits under the skin, often around the eyes, elbows, knees, or tendons. Arcus senilis, a grayish ring around the cornea, can indicate high cholesterol when it appears before age 45. These signs warrant immediate medical evaluation.

Health Risks of High Cholesterol

Elevated cholesterol is a major risk factor for cardiovascular disease, the leading cause of death worldwide. The damage occurs through atherosclerosis, a gradual process where cholesterol-laden plaques form in artery walls.

Heart Disease

Coronary artery disease develops when plaques narrow the arteries supplying the heart. This can cause stable angina (predictable chest pain with exertion) or lead to heart attacks when plaques rupture and block blood flow completely. The risk of heart disease rises steadily with higher LDL levels.

Stroke

High cholesterol contributes to stroke through multiple mechanisms. Plaques can form in arteries supplying the brain, or pieces of plaque can break off and travel to block smaller brain vessels. Ischemic stroke, caused by blocked blood flow, accounts for about 87% of all strokes.

Peripheral Artery Disease

The same plaque-building process affects arteries throughout the body. When leg arteries narrow, walking becomes painful, wounds heal poorly, and severe cases may require amputation. Peripheral artery disease also signals increased risk of heart attack and stroke.

Risk Factors That Compound High Cholesterol

High cholesterol rarely occurs in isolation. Other cardiovascular risk factors multiply the danger:

• High blood pressure: Damages artery walls, making them more susceptible to plaque buildup
• Diabetes: Accelerates atherosclerosis and damages blood vessels
• Smoking: Lowers HDL, damages arteries, and promotes inflammation
• Family history: Heart disease in close relatives indicates genetic susceptibility
• Obesity: Worsens multiple cardiovascular risk factors simultaneously
• Age: Risk accumulates over time

Someone with high cholesterol plus diabetes and high blood pressure faces far greater risk than someone with high cholesterol alone. This is why treatment recommendations consider your complete risk profile, not just your cholesterol numbers.

When to Seek Treatment

Everyone with high cholesterol should discuss it with their doctor. Whether treatment involves lifestyle changes alone or medication depends on your overall cardiovascular risk.

Lifestyle changes (diet, exercise, weight management) are recommended for nearly everyone with elevated cholesterol. These approaches can lower LDL by 10-20% in many people.

Medication, typically statins, is generally recommended when:

• You have existing cardiovascular disease (heart attack, stroke, peripheral artery disease)
• LDL is very high (190 mg/dL or above)
• You have diabetes and are age 40-75
• Your 10-year cardiovascular risk is 7.5% or higher
• Lifestyle changes haven't achieved adequate cholesterol reduction