High cholesterol means that you have too much cholesterol in your blood. There are many things that can cause this. If you don't take steps to lower high cholesterol, it can increase your risk of heart attack and stroke . Find out more about the types of cholesterol. What causes high cholesterol? Anyone can develop high cholesterol. Learn how to interpret your cholesterol test results and what they mean for your heart health. Find out the normal ranges, factors that affect your cholesterol levels, and how to lower them. See a video, an animation, and a PDF guide on cholesterol score and LDL cholesterol. Normal triglyceride levels vary by age and sex. People with high triglycerides often have a high total cholesterol level, including a high LDL (bad) cholesterol level and a low HDL (good) cholesterol level. Many people with metabolic syndrome or diabetes also have high triglyceride levels. Blood cholesterol is measured in units called millimoles per litre of blood, or mmol/L. As a rough guide, the total levels should be: 5 mmol/L or less for healthy adults. 4 mmol/L or less for those at high risk. LDL levels should be: 3 mmol/L or less for healthy adults. 2 mmol/L or less for those at high risk. High Cholesterol Facts Print Find up-to-date facts about high cholesterol in the United States. High total cholesterol in the United States Between 2017 and 2020, 10% of adults age 20 or older had total cholesterol levels above 240 mg/dL and about 17% had high-density lipoprotein (HDL, or "good") cholesterol levels below 40 mg/dL. 1 High blood pressure and high LDL (or "bad") cholesterol that is linked to genetics increases the risk of developing coronary heart disease throughout life, a new study reports. In addition .

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