LDL and HDL are two different types of lipoproteins. They both receive bad representation from the press because lipoproteins are usually good in moderation.
"HDL and LDL." University of Maryland Medical Center. Web. 23 Mar. 2015. <http://umm.edu/health/medical/reports/images/hdl-and-ldl>.
LDL is a type of lipoprotein (a protein and a lipid combined) it transports cholesterol to the cells. Usually LDL is shown as the bad cholesterol because there has been a large amount of misinformation spread around the media.
What is LDL?
HDL is known as the good cholesterol. HDL is responsible for removing excess cholesterol from the blood stream and transferring it to the liver. Unlike LDL cholesterol, the higher HDL in the blood stream the better it is for the body.
"How To Lower LDL Cholesterol Effectively." Savyy Health and Fitness Tips News and Reviews. 30 Aug. 2010. Web. 23 Mar. 2015. <http://savvyhealthfitness.com/get-healthy/cholesterol/how-to-lower-ldl-cholesterol-effectively>.
What Is hdl?
"HDL Composition." — Foods For Health Institute. Web. 23 Mar. 2015. <http://ffhi.ucdavis.edu/prog/lnp/proj/comp>.
A Doctor may be monitoring your blood because...
Everyone is at risk for high cholesterol problems. Even the healthiest people may have problems with their cholesterol. A doctor will look for high levels of LDL and low levels of HDL.
"What Is Atherosclerosis?" - NHLBI, NIH. Web. 19 Mar. 2015. <http://www.nhlbi.nih.gov/health/health-topics/topics/atherosclerosis>
"Understanding Cholesterol Levels: LDL, HDL, Total Cholesterol, and Triglyceride Levels."WebMD. WebMD. Web. 19 Mar. 2015. <http://www.webmd.com/cholesterol-management/guide/understanding-numbers>
"LDL Cholesterol: "The Bad Cholesterol"" WebMD. WebMD. Web. 19 Mar. 2015. <http://www.webmd.com/cholesterol-management/ldl-cholesterol-the-bad-cholester/