HDL AND LDL?what is the difference between HDL and LDL and what do they do?

LDL is a low density lipoprotein. It starts it's life as a very low density lipoprotein (VLDL) which transports fat in the form of triglycerides and cholesterol around the body. As it loses the triglycerides to cells for energy or storage, it becomes an LDL, containing mainly cholesterol.
Cholesterol is a vital substance within the body, so the purpose of LDL is to get the cholesterol to cells that need it. For the cholesterol to be transferred, a cell needs a specific receptor. Without this receptor there will be no transfer of cholesterol, so it's impossible for cholesterol to just clog up your arteries.. If you produce too many VLDLs, it will result in high levels of LDL as cells only have the receptor when they need cholesterol. Remember that unless cells have the receptor, the LDL cannot unload it's cargo.

A HDL is a high density lipoprotein. One of it's functions is to return 'used' cholesterol, from cells back to the liver.

This is a cyclic process. LDLs supply the cells with fresh cholesterol and HDLs remove the used cholesterol. Neither is good or bad, they both play an important role, without which we would simply die.

Another purpose of HDL is to hand out and take back things called appolipoproteins to VLDLs. These appolipoproteins are what activates the enzymes in your capillaries to transfer the triglycerides from the VLDLs to cells

HDL is good cholesterol. LDL is bad. You need a healthy proportion.

do your homework. lol.

HDL is High Density Lipids. LDL is Low Density Lipids. These are basically fat particles in your blood stream. They are essential for our survival. However, if they get too high they can clog up your artery walls and give you a heart attack or stroke.

It is the LDLs that are most problematic in high concentrations because the are more sticky than the HDLs.

HDL is the garbage man picking up the trash. LDL is the garbage man bringing trash to your house. HDL takes cholesterol away from arteries and LDL brings it there. But the latest discovery is that there is HARMFUL and HARMLESS LDL. See site below for more on that.

Cholesterol can鈥檛 dissolve in the blood. It has to be transported to and from the cells by carriers called lipoproteins. Low-density lipoprotein, or LDL, is known as 鈥渂ad鈥?cholesterol. High-density lipoprotein, or HDL, is known as 鈥済ood鈥?cholesterol. These two types of lipids, along with triglycerides and Lp(a) cholesterol, make up your total cholesterol count, which can be determined through a blood test.

LDL (Bad) Cholesterol
When too much LDL (bad) cholesterol circulates in the blood, it can slowly build up in the inner walls of the arteries that feed the heart and brain. Together with other substances, it can form plaque, a thick, hard deposit that can narrow the arteries and make them less flexible. This condition is known as atherosclerosis. If a clot forms and blocks a narrowed artery, heart attack or stroke can result.

HDL (good) Cholesterol
About one-fourth to one-third of blood cholesterol is carried by high-density lipoprotein (HDL). HDL cholesterol is known as 鈥済ood鈥?cholesterol, because high levels of HDL seem to protect against heart attack. Low levels of HDL (less than 40 mg/dL) also increase the risk of heart disease. Medical experts think that HDL tends to carry cholesterol away from the arteries and back to the liver, where it's passed from the body. Some experts believe that that HDL removes excess cholesterol from arterial plaque, thus slowing its buildup.

Triglycerides
Triglyceride is a form of fat made in the body. Elevated triglycerides can be due to overweight/obesity, physical inactivity, cigarette smoking, excess alcohol consumption and a diet very high in carbohydrates (60 percent of total calories or more). People with high triglycerides often have a high total cholesterol level, including a high LDL (bad) level and a low HDL (good) level. Many people with heart disease and/or diabetes also have high triglyceride levels.

Lp(a) Cholesterol
Lp(a) is a genetic variation of LDL (bad) cholesterol. A high level of Lp(a) is a significant risk factor for the premature development of fatty deposits in arteries. Lp(a) isn鈥檛 fully understood, but it may interact with substances found in artery walls and contribute to the buildup of fatty deposits.