Cholesterol testing uses a blood sample, sometimes called a lipid panel, to measure total, LDL (harmful), and HDL (protective) cholesterol plus triglycerides. High levels often cause no symptoms but build up in arteries over years, raising the risk of heart attack and stroke.
A reasonable default for healthy adults is a check every four to six years starting in your 20s, with more frequent testing as you age or if you have risk factors such as high blood pressure, diabetes, obesity, smoking, or a family history of early heart disease. Some inherited conditions cause very high cholesterol from a young age and warrant earlier screening.
Results are interpreted alongside your overall cardiovascular risk, not in isolation. Depending on that picture, a doctor may recommend lifestyle changes, repeat testing, or medication such as a statin. If you already take cholesterol medicine, your clinician will set the monitoring schedule.