Cholesterol is measured as several values: total cholesterol, LDL (the harmful type that builds up in arteries), HDL (the protective type), and triglycerides. As a general guide, total cholesterol under about 5 mmol/L (200 mg/dL) and LDL under about 3 mmol/L (130 mg/dL) are desirable, with higher HDL being better.
What counts as too high is not the same for everyone. Someone who has had a heart attack, has diabetes, or is at high cardiovascular risk will be given much lower LDL targets than a healthy young adult. Doctors interpret your numbers together with age, blood pressure, smoking, family history and other factors using a risk calculator.
A fasting or non-fasting lipid blood test is needed to know your levels. Discuss your results with a doctor, who can tell you your personal targets and whether lifestyle changes alone or medication are appropriate.