What Is Cholesterol?

Cholesterol is a natural substance made by the body. Most of the cholesterol in our bloodstream (75%) is produced by the liver, and the remaining 25% comes from the foods we eat. We all know that elevated blood cholesterol levels are not good for your health, but the right levels of cholesterol actually play a vital role in maintaining cell membranes and synthesizing hormones. The Centers for Disease Control reports that one-third of adults have high cholesterol levels.
A steroid alcohol C27H45OH that is present in animal cells and body fluids, regulates membrane fluidity, and functions as a precursor molecule in various metabolic pathways and as a constituent of LDL may cause atherosclerosis


COMPARISON BETWEEN BAD CHOLESTEROL, AND GOOD CHOLESTEROL
LDL (BAD) CHOLESTEROL
LDL cholesterol is considered the “bad” cholesterol because it contributes to plaque, a thick, hard deposit that can clog 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. Another condition called peripheral artery disease can develop when plaque buildup narrows an artery supplying blood to the legs.

HDL (Good) Cholesterol
HDL cholesterol is considered “good” cholesterol because it helps remove LDL cholesterol from the arteries. Experts believe HDL acts as a scavenger, carrying LDL cholesterol away from the arteries and back to the liver, where it is broken down and passed from the body. One-fourth to one-third of blood cholesterol is carried by HDL. A healthy level of HDL cholesterol may also protect against heart attack and stroke, while low levels of HDL cholesterol  have been shown to increase the risk of heart disease.


TRIGLYCERIDES
Triglycerides are another type of fat, and they're used to store excess energy from your diet. High levels of triglycerides in the blood are associated with atherosclerosis. Elevated triglycerides can be caused by overweight and obesity, physical inactivity, cigarette smoking, excess alcohol consumption and a diet very high in carbohydrates (more than 60 percent of total calories). Underlying diseases or genetic disorders are sometimes the cause of high triglycerides. People with high triglycerides often have a high total cholesterol level, including a high LDL cholesterol (bad) level and a low HDL cholesterol (good) level. Many people with heart disease or diabetes also have high triglyceride levels.