Cholesterol

Cholesterol is a waxy, fat-like substance in your blood that your body needs to build cells and make hormones. Your liver produces most of the cholesterol you need, but you also get some from foods like meat, eggs, and dairy products. The problem starts when you have too much cholesterol in your blood. Excess cholesterol deposits into artery walls, forming plaques that narrow blood vessels and restrict blood flow. Over decades, these plaques grow larger, and sometimes they rupture suddenly, triggering blood clots that cause heart attacks and strokes. High cholesterol has no symptoms—you feel completely fine while damage silently progresses. This is why knowing your cholesterol numbers through blood tests is crucial. Understanding the different types of cholesterol, what levels are healthy, and how to control them helps you prevent heart disease and strokes, the leading causes of death worldwide.

Overview

Cholesterol is essential for life. Your body uses it to build cell membranes, produce vitamin D, make bile acids that help digest fats, and create hormones like estrogen and testosterone. Your liver manufactures about 75% of the cholesterol in your body. The remaining 25% comes from food.

The problem isn’t cholesterol itself but having too much in your bloodstream. Excess cholesterol can’t dissolve in blood, so it travels attached to proteins called lipoproteins. Different types of lipoproteins carry cholesterol to different places and behave very differently.

Types of Cholesterol

Understanding the different types helps you interpret your blood test results.

• LDL (low-density lipoprotein), carries cholesterol from your liver to cells throughout your body. When you have too much LDL, it deposits into artery walls. This is why LDL is called “bad cholesterol.” The higher your LDL, the more plaque builds up in arteries.
• HDL (high-density lipoprotein), does the opposite. It picks up excess cholesterol from tissues and artery walls and transports it back to your liver for disposal. This is why HDL is called “good cholesterol.” The higher your HDL, the better.
• Triglycerides, are another type of fat in your blood. They’re not cholesterol but are measured in the same blood test. High triglycerides often accompany low HDL and contribute to artery disease.

The balance between these different fats determines your cardiovascular risk. You want low LDL, high HDL, and normal triglycerides.

Healthy Cholesterol Levels

What constitutes healthy cholesterol levels depends on your overall cardiovascular risk.

Total cholesterol below 200 mg/dL is considered desirable for healthy people. However, this number alone doesn’t tell the whole story—you need to know the breakdown between LDL and HDL.

LDL cholesterol targets vary based on your risk level. For healthy people with no risk factors, LDL below 100 mg/dL is optimal. For people with diabetes or multiple risk factors, the target is below 70 mg/dL. For those with known heart disease or very high risk, the goal is below 55 mg/dL or even lower.

The concept is simple: the higher your risk for heart attacks and strokes, the lower your LDL should be. There’s no lower limit where LDL becomes dangerous—lower is always better.

HDL cholesterol above 60 mg/dL is protective. Below 40 mg/dL in men or below 50 mg/dL in women is considered low and increases risk. Unlike LDL where lower is better, with HDL you want higher numbers.

Triglycerides should be below 150 mg/dL. Levels of 150-199 mg/dL are borderline high. Levels of 200-499 mg/dL are high. Levels above 500 mg/dL are very high and increase risk for pancreatitis—a serious inflammation of the pancreas.

These targets are guidelines. Your doctor determines your specific goals based on your age, other health conditions, family history, and whether you’ve had heart attacks or strokes.

What Causes High Cholesterol

Multiple factors determine your cholesterol levels, some you can control and others you can’t.

• Genetics is the most powerful factor you can’t change. Your genes determine how much cholesterol your liver produces, how efficiently your body removes LDL from blood, and how your body processes dietary fats. Some people inherit genes that naturally produce low cholesterol. Others inherit genes causing very high cholesterol despite healthy lifestyles.
• Familial hypercholesterolemia is a genetic condition affecting about 1 in 250 people. People with this condition have LDL levels of 200-400 mg/dL or higher from birth. Without treatment, they develop severe heart disease in their 30s, 40s, or even 20s.
• Diet influences cholesterol, though not as dramatically as most people think. Saturated fats found in red meat, butter, cheese, and coconut oil raise LDL. Trans fats found in some processed foods raise LDL even more and should be completely avoided. Dietary cholesterol from eggs and shellfish has less impact than previously believed.
• Eating patterns matter more than individual foods. Diets high in processed foods, saturated fats, and refined carbohydrates raise cholesterol. Diets emphasizing vegetables, fruits, whole grains, fish, and healthy fats lower it.
• Body weight affects cholesterol significantly. Being overweight lowers HDL and raises triglycerides. Weight loss improves lipid profiles—typically lowering LDL and triglycerides while raising HDL.
• Physical inactivity allows cholesterol levels to worsen. Regular exercise raises HDL and lowers triglycerides. The effect on LDL is modest but still beneficial.
• Age affects cholesterol. Levels tend to rise as you get older. Women typically have lower LDL than men until menopause, when their levels often increase.
• Medical conditions alter cholesterol. Diabetes lowers HDL and raises triglycerides. Hypothyroidism raises LDL significantly. Kidney disease and polycystic ovary syndrome both affect lipid metabolism.
• Medications can raise cholesterol as side effects. Some diuretics, beta-blockers, and steroids affect lipid levels. If you’re taking medications and your cholesterol is high, discuss this with your doctor—sometimes alternatives exist.
• Smoking lowers HDL and damages artery walls, making them more susceptible to cholesterol deposits.

Symptoms and Detection

High cholesterol itself causes no symptoms. You feel completely normal while plaque silently accumulates in arteries for decades. Symptoms only appear when plaque has narrowed arteries enough to restrict blood flow or when plaques rupture, causing heart attacks or strokes. By then, significant damage has occurred. This is why screening is crucial. The only way to know your cholesterol levels is through blood tests.

Guidelines recommend:

• Adults age 20 and older should have cholesterol checked every 4-6 years if they’re healthy with no risk factors. More frequent testing is appropriate if you have risk factors like diabetes, high blood pressure, family history of heart disease, obesity, or smoking.
• Children and adolescents should be screened once between ages 9-11 and again between ages 17-21. Earlier or more frequent testing is recommended if there’s family history of very high cholesterol or early heart disease.
• The standard test is a lipid panel measuring total cholesterol, LDL, HDL, and triglycerides. The test requires fasting for 9-12 hours beforehand for accurate triglyceride measurement, though some newer tests don’t require fasting.

Some people develop visible signs when cholesterol is extremely high. Xanthomas are yellowish deposits of cholesterol under the skin, often on eyelids, elbows, or knees. Corneal arcus is a white or grayish ring around the iris. These physical signs suggest very high cholesterol that needs immediate treatment.

Risks of High Cholesterol

High cholesterol’s main danger is cardiovascular disease—heart attacks, strokes, and peripheral artery disease.

Atherosclerosis is the underlying process. Excess LDL deposits into artery walls, forming plaques. These plaques grow slowly over decades, narrowing arteries and restricting blood flow.

Coronary artery disease develops when plaques narrow the arteries supplying your heart. This causes chest pain—angina—when your heart needs more oxygen than narrowed arteries can deliver, typically during exertion. If a plaque ruptures, it triggers a blood clot that completely blocks the artery, causing a heart attack. Part of your heart muscle dies from lack of oxygen.

Stroke occurs when plaques narrow arteries supplying your brain or when plaques rupture and clots block brain arteries. Brain tissue dies within minutes without oxygen.

Peripheral artery disease affects leg arteries. Narrowed arteries cause leg pain when walking—claudication. Severe cases lead to wounds that won’t heal or gangrene requiring amputation.

The risk increases with higher LDL and lower HDL. Someone with LDL of 200 mg/dL faces much higher risk than someone with LDL of 100 mg/dL. The relationship is continuous—there’s no safe threshold, just lower and higher risk.

Additional risk factors multiply the danger. High cholesterol combined with high blood pressure, diabetes, smoking, or family history creates exponentially higher risk than any single factor alone.

The good news: lowering cholesterol dramatically reduces these risks. For every 40 mg/dL reduction in LDL, major cardiovascular events decrease by about 20-25%. Starting treatment earlier in life provides greater benefit because you prevent decades of plaque accumulation.

Lowering Cholesterol Through Lifestyle

Lifestyle changes form the foundation of cholesterol management. Many people can significantly improve their numbers through healthy habits alone.

• Dietary changes make a real difference. Reduce saturated fat by choosing lean meats, poultry, and fish over fatty red meats. Use olive oil instead of butter. Choose low-fat dairy products. Limit cheese. Avoid trans fats completely by reading labels and avoiding partially hydrogenated oils.
• Increase foods that actively lower cholesterol. Soluble fiber from oats, beans, lentils, apples, pears, and barley binds cholesterol in your intestines and removes it. Aim for 5-10 grams of soluble fiber daily. Nuts—almonds, walnuts, pistachios—contain healthy fats that improve cholesterol. A small handful daily helps. Fatty fish like salmon, mackerel, and sardines contain omega-3 fatty acids that lower triglycerides.
• Plant sterols and stanols, found in fortified margarines and orange juice, block cholesterol absorption and can lower LDL by 5-10 mg/dL when consumed regularly.
• Weight loss powerfully improves lipid profiles if you’re overweight. Losing 5-10% of your body weight typically lowers LDL and triglycerides while raising HDL. Even modest weight loss helps.
• Regular exercise raises HDL and lowers triglycerides. Aim for at least 150 minutes of moderate activity weekly—brisk walking, swimming, cycling. Adding strength training twice weekly provides additional benefits.
• Quit smoking. Smoking cessation raises HDL by 5-10 mg/dL within weeks to months and provides numerous other cardiovascular benefits.
• Limit alcohol. While moderate drinking might raise HDL slightly, the risks often outweigh benefits. If you drink, limit to one drink daily for women, two for men.

These lifestyle changes work best when sustained long-term. They’re not quick fixes but permanent habit changes that protect your health for decades.

Medications for High Cholesterol

When lifestyle changes aren’t enough to reach target LDL levels, medications are highly effective and safe.

• Statins are the most commonly prescribed and most effective cholesterol-lowering drugs. They work by blocking an enzyme your liver needs to produce cholesterol. With less cholesterol being made, your liver pulls more LDL from your blood. Statins lower LDL by 30-50% on average.
• High-intensity statins like atorvastatin 40-80 mg or rosuvastatin 20-40 mg lower LDL by 50% or more. Moderate-intensity statins lower LDL by 30-40%. Your doctor chooses the intensity based on your target LDL level.
• Statins also stabilize existing plaques, reduce inflammation, and have other protective effects beyond cholesterol lowering. Decades of research prove they prevent heart attacks and strokes and save lives.
• Side effects are usually minor. Muscle aches affect about 5-10% of people but typically resolve when switching to different statins or lower doses. Serious muscle damage is extremely rare. Statins slightly increase diabetes risk in susceptible people, but cardiovascular benefits far outweigh this concern.
• Ezetimibe blocks cholesterol absorption in your intestines, lowering LDL by about 15-20%. It’s often combined with statins for greater LDL reduction. The combination provides more benefit than either drug alone.
• PCSK9 inhibitors are powerful injectable medications given every 2-4 weeks. They lower LDL by 50-60% beyond what statins achieve, allowing LDL to drop to very low levels—often below 30 mg/dL. They’re expensive and typically reserved for people at very high risk or those who can’t tolerate statins. They dramatically reduce heart attacks and strokes in appropriate patients.
• Bempedoic acid is a newer oral medication similar to statins but working through a slightly different pathway. It lowers LDL by 15-25% and is an option for people who can’t tolerate statins.
• Fibrates primarily lower triglycerides and modestly raise HDL. They’re used mainly when triglycerides are very high.
• Niacin (vitamin B3) in high doses raises HDL significantly but hasn’t proven to reduce heart attacks or strokes beyond what statins provide. Side effects including flushing limit its use.

The key to medication success is taking them consistently. These drugs prevent future problems rather than treating current symptoms, so people sometimes stop taking them because they feel fine. Don’t stop cholesterol medications without consulting your doctor—doing so allows LDL to rise again and atherosclerosis to progress.

Key Points

• Cholesterol is a waxy substance in your blood essential for building cells and making hormones, but too much causes heart disease and strokes.
• LDL cholesterol is “bad cholesterol” that deposits into artery walls, forming plaques. The higher your LDL, the greater your risk. Lowering LDL prevents heart attacks and strokes.
• HDL cholesterol is “good cholesterol” that removes excess cholesterol from arteries. Higher HDL levels are protective.
• High cholesterol causes no symptoms. You feel completely normal while damage silently progresses for decades. The only way to know your levels is through blood tests.
• Healthy LDL targets depend on your overall risk. For healthy people, aim for LDL below 100 mg/dL. For those with diabetes or heart disease, targets are much lower—below 70 or even 55 mg/dL.
• Genetics powerfully influences cholesterol levels. Some people inherit genes causing very high cholesterol despite healthy lifestyles.
• Diet affects cholesterol. Saturated fats and trans fats raise LDL. Soluble fiber, nuts, and fatty fish help lower it. Weight loss improves cholesterol if you’re overweight.
• Lifestyle changes including healthy eating, regular exercise, weight loss, and not smoking form the foundation of treatment.
• Statins are highly effective medications that lower LDL by 30-50% and prevent heart attacks and strokes. They’re safe for most people and should be taken consistently.
• Additional medications including ezetimibe and PCSK9 inhibitors further lower LDL when needed.
• Lowering cholesterol dramatically reduces cardiovascular risk. For every 40 mg/dL reduction in LDL, major cardiovascular events decrease by about 20-25%. Starting treatment earlier provides greater lifelong benefit.
• Work with your doctor to know your cholesterol numbers, understand your cardiovascular risk, and develop an appropriate treatment plan combining lifestyle changes and medications when needed.

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LDL Cholesterol

Reference: Cholesterol