Cholesterol (Lipid) Test

What it is

A lipid panel, also called a lipid profile, reports four figures from one blood sample: total cholesterol, LDL, HDL and triglycerides. The point of splitting cholesterol into LDL and HDL is that they behave differently in the arteries, and the balance between them carries more meaning than the total alone. In most laboratories the LDL figure is calculated from the other three rather than measured directly. Unlike most blood tests, this one is rarely ordered because something is wrong right now. It is ordered to estimate what is likely to happen over years.

Why it is done

• To estimate the risk of heart and blood vessel disease in someone without symptoms, which is the most common reason it is drawn
• To decide whether treatment aimed at lowering cholesterol is worth starting
• To check whether treatment already underway is having the intended effect
• To investigate a strong family history of early heart disease or of inherited cholesterol disorders

What to expect

Blood is drawn from a vein in the arm. Fasting for roughly nine to twelve hours beforehand is often requested, which is why these draws tend to be booked first thing in the morning, though not every clinician requires it and the instruction should come from the one who ordered the test. Results come back within a day or so. How often the test is repeated depends on age and risk factors rather than on any fixed schedule, and a single set of numbers matters less than the trend across several.

Questions worth asking

• Is this coded as preventive screening or as a diagnostic test? Many plans cover screening lipid panels with no cost sharing and treat the diagnostic version differently.
• If it was ordered during an office visit, is the visit billed separately from the lab work?
• Is the blood being drawn at the clinic and sent out? The draw site and the testing lab can each generate a charge, and they are not always in the same network.
• If the result is abnormal, what follow-up testing is likely, and what does that add before any treatment starts?