Cholesterol
Cholesterol is a waxy fat-like substance the body needs, but unhealthy blood cholesterol levels can raise the risk of plaque buildup, heart disease, and stroke.
What cholesterol is
Cholesterol is a waxy, fat-like substance found in the body's cells and in some foods from animals. The liver makes cholesterol, and the body uses it for cell membranes, hormones, vitamin D, and bile acids. Problems arise when blood cholesterol patterns increase the chance of fatty deposits building inside artery walls.
LDL, HDL, and triglycerides
Cholesterol does not float through blood by itself. It is carried in particles called lipoproteins. LDL cholesterol is often called bad because higher levels can contribute to plaque buildup in arteries. HDL cholesterol is often called good because it helps carry cholesterol back to the liver. Triglycerides are another blood fat that can add risk when elevated.
Plaque and arteries
When excess cholesterol enters artery walls, inflammation and other processes can help form plaque. Plaque can narrow arteries over time, making it harder for blood to flow. If a plaque ruptures, a clot can form and block blood flow, causing a heart attack or stroke depending on where the blockage happens.
Testing
A lipid panel is a blood test that commonly reports total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides. Some tests require fasting, while others may not, depending on the purpose and clinician guidance. Results are interpreted with age, blood pressure, diabetes, smoking, kidney disease, family history, and other cardiovascular risk factors.
Risk factors
Cholesterol levels are shaped by both biology and environment. Diet patterns high in saturated fat or trans fat, low physical activity, tobacco exposure, higher body weight, diabetes, some kidney or thyroid conditions, age, family history, and inherited cholesterol disorders can all affect risk. Some people have high LDL even with careful habits.
Lowering cholesterol
Lowering risk can involve eating patterns that emphasize vegetables, fruits, whole grains, beans, nuts, unsaturated fats, and fish while limiting saturated fat and avoiding trans fat. Physical activity, not smoking, weight management when relevant, and controlling diabetes or blood pressure can help. Medicines such as statins may be recommended when risk remains high.
Medicines and decisions
Treatment decisions are not based on one number alone. Clinicians often estimate overall cardiovascular risk, review prior heart attack or stroke history, look for diabetes or inherited cholesterol conditions, and discuss benefits, side effects, costs, pregnancy plans, and preferences. Follow-up testing can show whether the plan is working.
Why it matters
Cholesterol matters because it is both invisible and modifiable. A person may feel well for years while plaque risk builds, yet testing and treatment can reveal a risk that can be lowered. It also connects individual choices to food systems, preventive care access, medication affordability, and long-term public health.