Low density lipoprotein (LDL)

This test measures the bad cholesterol. LDL can be decreased by healthy eating, exercise, and certain medications.

Low density lipoprotein (LDL) Overview

Reviewed: April 22, 2014

Low density lipoprotein (LDL) is considered the bad cholesterol. LDL carries cholesterol from the liver to other parts of the body where it can clog blood vessels. It can be higher due to some of the high-fat foods in the diet and/or genetics. The principal use for LDL measurements is in the assessment of CHD risk.

LDL is measured in milligram per deciliter (mg/dL). The ranges for LDL are the following:

  • Optimal: <100 mg/dL
  • Near optimal/above optimal: <100-129 mg/dL
  • Borderline high: 130-159 mg/dL
  • High: 160-189 mg/dL
  • Very high: >189 mg/dL


Blood draw


Fasting 12 hours before the test is required.

Water intake is allowed.

What the results mean

The higher the value, the greater the risk for atherosclerosis (thickening and hardening of arteries), and therefore the greater the risk for heart attack and stroke. LDL may be increased by thiazides, beta blockers, estrogens, and other drugs.

LDL may be decreased by fish oils, statins, niacin, fibrates, estrogens, and other drugs.