Which test determines blood cholesterol levels, including HDL and LDL and their ratio?

• A. Calcium test
• B. Complete blood count
• C. Blood urea nitrogen (BUN)
• D. Cholesterol test

Answer: (D)

Measuring blood cholesterol levels, including HDL and LDL, and their ratio, is done with a cholesterol test. This test analyzes blood lipids to provide values for total cholesterol, high-density lipoprotein (HDL), and low-density lipoprotein (LDL), often along with triglycerides. From these numbers, ratios like total cholesterol to HDL or LDL to HDL are calculated because they more accurately reflect cardiovascular risk than any single value. HDL helps remove cholesterol from arteries, offering protection, while LDL carries cholesterol toward arterial walls, promoting plaque buildup. An unfavorable ratio—high LDL and/or low HDL—indicates higher risk and can guide lifestyle or medication decisions to reduce risk.

Other tests measure different things: a calcium test checks mineral levels for bone and other functions; a complete blood count evaluates blood cells to screen for anemia, infection, and other conditions; and blood urea nitrogen assesses kidney function. The cholesterol test targets lipids and cardiovascular risk specifically.