High Cholesterol: Symptoms, Causes & Treatment

What Is High Cholesterol and Why Does It Matter?

High cholesterol (hyperlipidemia) is a condition where you have elevated levels of fats (lipids) in your blood, particularly LDL cholesterol and triglycerides. These fats can accumulate in your artery walls, forming plaques that narrow and stiffen the arteries (atherosclerosis), eventually leading to serious cardiovascular diseases such as heart attack and stroke.

Cholesterol is a waxy, fat-like substance that your body needs to build cells, make hormones, and produce vitamin D. Your liver produces all the cholesterol your body needs, but you also get cholesterol from foods you eat, particularly animal products like meat, eggs, and dairy. While cholesterol is essential for life, too much of certain types can be harmful to your cardiovascular health.

The term "blood lipids" encompasses several types of fats circulating in your bloodstream, with cholesterol and triglycerides being the most clinically significant. Understanding the different types of cholesterol and what your numbers mean is crucial for protecting your heart health. Approximately 38% of adults worldwide have elevated total cholesterol levels above 5.0 mmol/L (200 mg/dL), making this one of the most common cardiovascular risk factors globally.

Cardiovascular disease remains the leading cause of death worldwide, claiming approximately 17.9 million lives each year according to the World Health Organization. High cholesterol is a major modifiable risk factor for these conditions, which means that managing your cholesterol levels can significantly reduce your risk of heart attack, stroke, and other serious health problems. The relationship between cholesterol and cardiovascular disease has been established through decades of rigorous scientific research, including landmark studies like the Framingham Heart Study.

The Different Types of Cholesterol

Cholesterol travels through your bloodstream attached to proteins called lipoproteins. The two main types you'll hear about are LDL (low-density lipoprotein) and HDL (high-density lipoprotein), often referred to as "bad" and "good" cholesterol respectively. Understanding the difference between these is fundamental to understanding your cholesterol numbers and cardiovascular risk.

LDL cholesterol (the "bad" cholesterol) carries cholesterol particles throughout your body. LDL cholesterol builds up in the walls of your arteries, making them hard and narrow. This process, called atherosclerosis, is the underlying cause of most cardiovascular events. When LDL cholesterol oxidizes in the artery wall, it triggers an inflammatory response that leads to plaque formation. Over time, these plaques can rupture and cause blood clots that block blood flow, resulting in heart attacks or strokes.

HDL cholesterol (the "good" cholesterol) picks up excess cholesterol from your bloodstream and artery walls and transports it back to your liver, where it can be processed and eliminated from the body. This process is called "reverse cholesterol transport" and is one of the body's primary defense mechanisms against atherosclerosis. Higher levels of HDL cholesterol are associated with lower cardiovascular risk, which is why it's often called "good" cholesterol.

Triglycerides are another type of fat in your blood. They store excess energy from your diet and are released between meals for fuel. Elevated triglyceride levels, particularly when combined with high LDL and low HDL, significantly increase cardiovascular risk. High triglycerides are often associated with obesity, poorly controlled diabetes, excessive alcohol consumption, and a diet high in refined carbohydrates and sugars.

What Are the Symptoms of High Cholesterol?

High cholesterol typically causes no symptoms at all, which is why it's often called a "silent" condition. Most people discover they have high cholesterol only through routine blood tests. However, some rare physical signs may develop, including yellowish fatty deposits around the eyes (xanthelasma) or near joints and tendons (xanthomas), particularly in people with familial hypercholesterolemia.

The silent nature of high cholesterol makes it particularly dangerous because the condition can progress for years or even decades without any warning signs. During this time, cholesterol continues to accumulate in the artery walls, gradually narrowing the blood vessels and increasing the risk of sudden cardiovascular events. This is precisely why regular cholesterol screening is so important – it's the only way to detect elevated levels before serious damage occurs.

In most cases, high cholesterol produces no outward physical symptoms whatsoever. You cannot feel your arteries becoming clogged, and there's no pain associated with cholesterol buildup itself. Many people only become aware of their high cholesterol when they experience a cardiovascular event such as angina (chest pain), heart attack, or stroke – at which point significant arterial damage has already occurred. This underscores the critical importance of preventive screening and early intervention.

Rare Physical Signs of Very High Cholesterol

While most people with high cholesterol have no visible signs, some individuals with very high cholesterol levels, particularly those with familial hypercholesterolemia (a genetic condition causing extremely elevated LDL cholesterol from birth), may develop certain physical manifestations over time:

• Xanthelasma: Yellowish, waxy deposits under the skin around the eyes, particularly on the eyelids. These soft, flat plaques are composed of cholesterol-laden cells and can appear even in people with normal cholesterol levels, though they're more common with elevated cholesterol.
• Xanthomas: Fatty lumps that form under the skin, typically near joints (especially elbows and knees) and along tendons (particularly the Achilles tendon). These are more specifically associated with familial hypercholesterolemia and indicate severely elevated cholesterol levels.
• Arcus senilis (corneal arcus): A grayish-white ring that appears around the edge of the cornea (the clear front surface of the eye). While this is common in older adults, its presence in younger individuals may indicate high cholesterol levels.

If you notice any of these physical signs, especially at a younger age, it's important to consult a healthcare provider promptly. These manifestations may indicate familial hypercholesterolemia, a genetic condition that requires aggressive treatment to prevent premature cardiovascular disease.

What Causes High Cholesterol?

High cholesterol is caused by a combination of factors including an unhealthy diet high in saturated and trans fats, lack of physical activity, obesity, smoking, and genetic factors. Some people inherit genes that cause their bodies to produce too much cholesterol (familial hypercholesterolemia), while others develop high cholesterol due to certain medical conditions or medications.

Understanding the causes of high cholesterol is essential for both prevention and treatment. While you cannot change factors like your age, sex, or genetics, many of the causes of high cholesterol are modifiable through lifestyle changes. By identifying and addressing the factors contributing to your elevated cholesterol, you can take meaningful steps toward improving your cardiovascular health.

Lifestyle Factors

Your daily habits and lifestyle choices have a profound impact on your cholesterol levels. These factors are largely within your control, which means you have significant power to influence your cholesterol numbers through the choices you make:

Diet plays a central role in cholesterol levels. Consuming foods high in saturated fats (found in red meat, full-fat dairy products, and tropical oils like coconut and palm oil) raises LDL cholesterol. Trans fats, found in some commercially baked goods, fried foods, and processed foods, are particularly harmful as they both raise LDL and lower HDL. Dietary cholesterol from foods like egg yolks and organ meats has a smaller effect than saturated fat but can still contribute to elevated levels in some individuals.

Physical inactivity contributes to weight gain and negatively affects cholesterol levels. Regular exercise helps raise HDL (good) cholesterol while also helping to maintain a healthy weight. Sedentary behavior, including prolonged sitting, has been independently associated with metabolic abnormalities including dyslipidemia.

Obesity, particularly abdominal obesity (excess fat around the waist), is strongly associated with high LDL cholesterol, high triglycerides, and low HDL cholesterol. This metabolic pattern, sometimes called atherogenic dyslipidemia, significantly increases cardiovascular risk. Losing even a modest amount of weight (5-10% of body weight) can meaningfully improve cholesterol levels.

Smoking damages the walls of your blood vessels, making them more susceptible to the accumulation of fatty deposits. Smoking also lowers HDL cholesterol and makes LDL cholesterol more prone to oxidation, which accelerates atherosclerosis. Quitting smoking can improve HDL levels within weeks and significantly reduce cardiovascular risk over time.

Excessive alcohol consumption can raise total cholesterol and triglyceride levels. While moderate alcohol intake has been associated with higher HDL levels in some studies, the potential risks of alcohol consumption generally outweigh this potential benefit.

Genetic and Medical Factors

Familial hypercholesterolemia (FH) is an inherited condition that affects approximately 1 in 250 people worldwide, making it one of the most common genetic disorders. People with FH have LDL cholesterol levels that are significantly higher than normal from birth due to genetic mutations affecting the LDL receptor or related proteins. Without treatment, individuals with FH have a dramatically increased risk of early-onset heart disease, sometimes occurring in their 30s or 40s.

Age and sex also influence cholesterol levels. Before menopause, women typically have lower LDL and higher HDL levels than men of the same age, likely due to the protective effects of estrogen. After menopause, women's LDL levels tend to rise, and their cardiovascular risk increases. In general, cholesterol levels tend to rise with age in both sexes.

Certain medical conditions can contribute to high cholesterol, including hypothyroidism (underactive thyroid), chronic kidney disease, diabetes, and liver disease. Managing these underlying conditions is an important part of cholesterol management.

Some medications can also affect cholesterol levels. Certain diuretics, beta-blockers, steroids, immunosuppressants, and antiviral medications may raise LDL or triglycerides. If you're concerned about medication effects on your cholesterol, discuss this with your healthcare provider – never stop taking prescribed medications without medical guidance.

How Is High Cholesterol Diagnosed?

High cholesterol is diagnosed through a simple blood test called a lipid panel or lipid profile. This test measures your total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides. The test is typically done after fasting for 9-12 hours to get accurate triglyceride and LDL measurements. Adults should have their cholesterol checked at least every 4-6 years, or more frequently if they have risk factors.

Because high cholesterol has no symptoms, regular screening through blood tests is the only way to know your cholesterol levels. The good news is that the test is simple, widely available, and relatively inexpensive. Understanding when to get tested and what the results mean empowers you to take control of your cardiovascular health.

When Should You Get Your Cholesterol Checked?

Screening recommendations vary slightly between different health organizations, but general guidelines suggest that adults aged 20 and older should have their cholesterol measured at least once every 4 to 6 years. More frequent testing may be recommended if you have risk factors for cardiovascular disease, including:

• Family history of high cholesterol or premature heart disease
• Diabetes or prediabetes
• High blood pressure
• Smoking
• Overweight or obesity
• Previous abnormal cholesterol results
• Treatment with cholesterol-lowering medications (monitoring every 3-12 months)

Children and adolescents from high-risk families (those with familial hypercholesterolemia or premature cardiovascular disease) should also be screened, typically between ages 2 and 10 for the first test. Universal screening of children is recommended between ages 9-11 and again between 17-21 according to some guidelines.

Understanding Your Cholesterol Numbers

Your lipid panel results will include several numbers, each measured in millimoles per liter (mmol/L) or milligrams per deciliter (mg/dL), depending on your country. Here are the generally desirable levels for the general population:

It's important to understand that these are general guidelines. Your individual target levels may differ based on your overall cardiovascular risk profile. For example, people who have already had a heart attack or stroke, those with diabetes, or those at very high cardiovascular risk may need to achieve much lower LDL levels (below 1.4 mmol/L or 55 mg/dL according to recent European guidelines).

Additional Tests

In some cases, your doctor may order additional tests to better understand your cardiovascular risk or to investigate underlying causes of high cholesterol:

• Apolipoprotein B (ApoB): A more accurate measure of atherogenic particles than LDL cholesterol alone
• Lipoprotein(a) [Lp(a)]: An inherited risk factor that may increase cardiovascular risk independently of LDL
• Thyroid function tests: To rule out hypothyroidism as a cause of high cholesterol
• Blood glucose/HbA1c: To check for diabetes, which often coexists with dyslipidemia
• Liver and kidney function tests: To assess for conditions affecting cholesterol metabolism
• Genetic testing: If familial hypercholesterolemia is suspected

What Can You Do to Lower Your Cholesterol?

Lifestyle modifications are the foundation of cholesterol management and can reduce LDL cholesterol by 10-20%. Key changes include eating a heart-healthy diet low in saturated and trans fats, exercising regularly (at least 150 minutes per week), maintaining a healthy weight, quitting smoking, and limiting alcohol. These changes benefit everyone with high cholesterol and may be sufficient for those with mildly elevated levels.

Before turning to medication, or alongside medication for those who need it, lifestyle changes are crucial for managing cholesterol and reducing cardiovascular risk. Even if you're taking cholesterol-lowering drugs, healthy habits amplify the benefits and address other cardiovascular risk factors that medications don't target.

Heart-Healthy Diet

Dietary changes are one of the most powerful tools for lowering cholesterol naturally. The overall quality of your diet matters more than any single food, so focus on building a sustainable eating pattern rather than eliminating individual items:

Reduce saturated fats: Saturated fats, found primarily in red meat, full-fat dairy products, and tropical oils (coconut and palm oil), raise LDL cholesterol. Limit saturated fat to less than 7% of your daily calories. Replace saturated fats with healthier unsaturated fats from olive oil, nuts, seeds, and fatty fish.

Eliminate trans fats: Trans fats (partially hydrogenated oils) are particularly harmful, raising LDL while lowering HDL. While many countries have banned or restricted trans fats in food production, they may still be found in some commercially baked goods, fried foods, and processed snacks. Check food labels and avoid products containing partially hydrogenated oils.

Increase soluble fiber: Soluble fiber reduces the absorption of cholesterol in your digestive tract. Good sources include oats, barley, beans, lentils, apples, pears, and psyllium. Aim for at least 5-10 grams of soluble fiber daily for a meaningful cholesterol-lowering effect.

Eat more omega-3 fatty acids: While omega-3s don't directly lower LDL cholesterol, they have heart-protective effects including reducing triglycerides, lowering blood pressure, and reducing inflammation. Excellent sources include fatty fish (salmon, mackerel, sardines, herring), walnuts, and flaxseeds. Aim for at least two servings of fatty fish per week.

Consider plant sterols and stanols: These plant compounds, structurally similar to cholesterol, block cholesterol absorption in the intestine. Consuming 2 grams per day can lower LDL by approximately 10%. They're found naturally in small amounts in many plants but are also added to fortified foods like certain margarines, orange juice, and yogurt drinks.

Embrace the Mediterranean diet pattern: This eating pattern, emphasizing vegetables, fruits, whole grains, legumes, nuts, olive oil, fish, and moderate wine consumption with meals, has been shown in numerous studies to reduce cardiovascular events. The PREDIMED trial demonstrated a 30% reduction in major cardiovascular events with a Mediterranean diet supplemented with olive oil or nuts.

Regular Physical Activity

Exercise is a powerful tool for improving cholesterol levels and overall cardiovascular health. Physical activity raises HDL cholesterol while helping to maintain a healthy weight. The benefits extend beyond cholesterol to include improved blood pressure, blood sugar control, and stress reduction.

Aerobic exercise (cardio) is particularly beneficial for cholesterol. Aim for at least 150 minutes of moderate-intensity aerobic activity (brisk walking, cycling, swimming) or 75 minutes of vigorous activity (running, aerobic dancing) per week. Even more benefit occurs with 300 minutes per week. Breaking this into shorter sessions (even 10-minute walks) throughout the day is effective.

Resistance training (strength training) also contributes to cardiovascular health and metabolic function. Include muscle-strengthening activities targeting all major muscle groups at least twice per week.

If you've been sedentary, start slowly and gradually increase duration and intensity. Any physical activity is better than none, and you'll see benefits even before reaching the recommended targets. Consult your healthcare provider before starting a new exercise program, especially if you have existing health conditions.

Weight Management

Carrying excess weight, particularly around your midsection, contributes to high LDL cholesterol, high triglycerides, and low HDL cholesterol. Losing weight can improve all of these numbers. Studies show that losing just 5-10% of your body weight can produce meaningful improvements in lipid levels.

Focus on sustainable weight loss through a combination of dietary changes and increased physical activity rather than crash diets. A modest calorie deficit of 500-750 calories per day typically leads to safe weight loss of 0.5-1 kg (1-2 pounds) per week.

Quit Smoking

Quitting smoking is one of the most important things you can do for your cardiovascular health. Within 20 minutes of quitting, your blood pressure and heart rate begin to recover. Within a year, your heart disease risk is half that of a continuing smoker. HDL cholesterol levels improve within weeks of quitting.

If you need help quitting, speak with your healthcare provider about cessation aids such as nicotine replacement therapy, prescription medications, or counseling programs. Many people need multiple attempts before successfully quitting, so don't be discouraged by setbacks.

Limit Alcohol

While moderate alcohol consumption has been associated with higher HDL levels in some studies, the potential harms of alcohol (including increased triglycerides, weight gain, liver damage, and addiction risk) generally outweigh this benefit. If you don't drink, don't start. If you do drink, limit intake to no more than one drink per day for women and two drinks per day for men.

How Is High Cholesterol Treated with Medication?

When lifestyle changes alone aren't sufficient to reach cholesterol goals, medications may be prescribed. Statins are the first-line treatment and the most effective drugs for lowering LDL cholesterol (25-50% reduction). Other medications include ezetimibe, PCSK9 inhibitors, bile acid sequestrants, and fibrates. Treatment decisions are based on your overall cardiovascular risk, not just your cholesterol numbers.

While lifestyle modifications are the foundation of cholesterol management, many people also need medication to reach their cholesterol goals and adequately reduce their cardiovascular risk. This is particularly true for those with established cardiovascular disease, diabetes, very high LDL levels, or multiple risk factors.

Statins: The Cornerstone of Cholesterol Treatment

Statins (HMG-CoA reductase inhibitors) are the most widely prescribed and most effective cholesterol-lowering medications. They work by blocking an enzyme your liver needs to produce cholesterol, which causes the liver to remove more LDL from your bloodstream. Commonly prescribed statins include atorvastatin (Lipitor), rosuvastatin (Crestor), simvastatin (Zocor), and pravastatin (Pravachol).

Statins typically reduce LDL cholesterol by 25-50%, depending on the specific drug and dose. Beyond lowering cholesterol, statins have additional beneficial effects including stabilizing arterial plaques, reducing inflammation, and improving blood vessel function. These "pleiotropic effects" contribute to their cardiovascular benefits.

Effectiveness: Large clinical trials have consistently demonstrated that statins reduce the risk of heart attack, stroke, and cardiovascular death by 20-30% in patients at elevated risk. For every 1 mmol/L (39 mg/dL) reduction in LDL cholesterol, there's approximately a 22% reduction in major cardiovascular events.

Safety: Statins are generally very safe and well-tolerated. The most common side effect is muscle aches, affecting approximately 5-10% of users. Most muscle symptoms are mild and manageable by adjusting the dose or switching to a different statin. Rare but serious side effects include severe muscle damage (rhabdomyolysis) and liver problems, which is why periodic monitoring may be recommended.

Many concerns about statins have been exaggerated in popular media. The risk of developing diabetes is slightly increased with statin use, but this risk is far outweighed by the cardiovascular benefits in those for whom statins are recommended. There is no convincing evidence that statins cause memory problems or cognitive decline.

Other Cholesterol-Lowering Medications

When statins alone don't achieve sufficient LDL reduction, or for patients who cannot tolerate statins, other medications may be used:

Ezetimibe (Zetia): Works in the small intestine to block cholesterol absorption. Reduces LDL by an additional 15-20% when added to a statin. Can also be used alone for statin-intolerant patients.

PCSK9 inhibitors (evolocumab, alirocumab): Powerful injectable medications that can reduce LDL by 50-60%, even when added to maximum statin therapy. Reserved for patients at very high risk who don't reach goals with other therapies, or for familial hypercholesterolemia. Given as subcutaneous injections every 2-4 weeks.

Bempedoic acid (Nexletol): A newer oral medication that works along the same metabolic pathway as statins but doesn't affect muscles. Can be used for patients who cannot tolerate statins due to muscle symptoms.

Bile acid sequestrants (cholestyramine, colesevelam): Bind to bile acids in the intestine, forcing the liver to use more cholesterol to make new bile acids. Can lower LDL by 15-30% but may cause digestive side effects and can interfere with other medications.

Fibrates (fenofibrate, gemfibrozil): Primarily used for high triglycerides. Can lower triglycerides by 25-50% and modestly raise HDL.

Niacin (nicotinic acid): Once commonly used to raise HDL and lower triglycerides, niacin is now rarely recommended due to side effects and lack of cardiovascular benefit in clinical trials when added to statin therapy.

Inclisiran: A novel siRNA therapy given as injection twice yearly that can reduce LDL by approximately 50%. Recently approved in some countries for patients not reaching goals on other therapies.

Treatment Goals and Approach

Modern guidelines emphasize that treatment intensity should be matched to cardiovascular risk. The higher your risk, the more aggressively cholesterol should be lowered. Cardiovascular risk is assessed using tools that consider multiple factors including age, sex, blood pressure, smoking status, diabetes, and existing cardiovascular disease.

For patients who have already had a heart attack or stroke, or who have established atherosclerotic cardiovascular disease, the goal is typically to reduce LDL by at least 50% from baseline and to achieve an LDL below 1.8 mmol/L (70 mg/dL) or even below 1.4 mmol/L (55 mg/dL) for very high-risk patients. For primary prevention in people without established disease, targets are less stringent but still emphasize meaningful LDL reduction for those at elevated risk.

What Happens If High Cholesterol Is Left Untreated?

Untreated high cholesterol leads to atherosclerosis – the gradual buildup of fatty plaques in artery walls. Over time, this narrows and stiffens the arteries, restricting blood flow. This process can ultimately cause heart attack (if coronary arteries are affected), stroke (if brain arteries are affected), peripheral artery disease (if leg arteries are affected), and other serious cardiovascular complications.

High cholesterol is dangerous precisely because it silently damages your cardiovascular system over years or decades before causing any symptoms. Understanding the serious consequences of untreated high cholesterol can motivate action to address it early, before irreversible damage occurs.

Atherosclerosis: The Underlying Problem

When there's too much LDL cholesterol in your blood, it begins to accumulate in the walls of your arteries. Once in the artery wall, LDL particles become oxidized, triggering an inflammatory response. White blood cells (macrophages) arrive to try to clean up the oxidized cholesterol but become overwhelmed and die, forming the core of an atherosclerotic plaque.

Over time, these plaques grow and harden, narrowing the artery and reducing blood flow. The plaques can also become unstable and rupture, triggering the formation of a blood clot that can completely block the artery or travel elsewhere in the body to cause blockages.

Complications of Atherosclerosis

Coronary artery disease (CAD): When atherosclerosis affects the arteries supplying the heart muscle, it causes coronary artery disease. This can manifest as angina (chest pain or discomfort during exertion) or, if a plaque ruptures and causes complete blockage, a heart attack (myocardial infarction). Heart attacks can cause permanent damage to the heart muscle, heart failure, dangerous arrhythmias, or sudden death.

Stroke: Atherosclerosis in the arteries supplying the brain, or the formation of clots that travel to the brain, can cause stroke. A stroke occurs when blood flow to part of the brain is interrupted, causing brain cells to die. Depending on the location and severity, strokes can cause paralysis, speech problems, cognitive impairment, or death.

Peripheral artery disease (PAD): When atherosclerosis affects the arteries supplying the limbs, particularly the legs, it causes peripheral artery disease. Symptoms include leg pain with walking (claudication), numbness, weakness, coldness in the lower leg or foot, and in severe cases, non-healing wounds or gangrene that may require amputation.

Chronic kidney disease: Atherosclerosis can damage the blood vessels in the kidneys, impairing their function over time and potentially leading to kidney failure.

How Can You Prevent High Cholesterol?

Preventing high cholesterol involves the same healthy habits used to treat it: eating a heart-healthy diet low in saturated and trans fats, exercising regularly, maintaining a healthy weight, not smoking, and limiting alcohol. Regular cholesterol screening allows early detection and intervention. For those with familial hypercholesterolemia, early diagnosis through family screening and prompt treatment are essential.

Prevention is always better than treatment. By adopting heart-healthy habits early in life and maintaining them, you can significantly reduce your risk of developing high cholesterol and its cardiovascular complications. Even if you already have risk factors you can't change, like family history, a healthy lifestyle can help minimize their impact.

Start healthy habits early: Atherosclerosis begins in childhood and progresses silently over decades. Teaching children healthy eating habits and an active lifestyle establishes patterns that protect them throughout life. Limiting processed foods, sugary drinks, and sedentary screen time while encouraging physical activity and whole foods creates a foundation for cardiovascular health.

Know your family history: If close relatives (parents, siblings, or children) have had high cholesterol or premature cardiovascular disease (before age 55 in men or 65 in women), you may be at increased risk. Share this information with your healthcare provider and consider earlier or more frequent screening.

Get screened regularly: Since high cholesterol has no symptoms, regular blood tests are essential for early detection. Follow screening recommendations for your age and risk profile, and don't wait until you have symptoms to check your cholesterol.

Address other risk factors: High cholesterol rarely exists in isolation. Managing blood pressure, blood sugar (if you have diabetes or prediabetes), and other cardiovascular risk factors multiplies the benefit of cholesterol control.