What Is Cholesterol?Cholesterol is a lipid belonging to the sterol family, it is an essential part of the membranes that surround the cells and is also essential for the production of hormones produced by the genital and adrenal glands. Cholesterol comes from 30% of the diet and 70% of the liver. This lipid is not soluble, it is transported in the body by proteins called lipoproteins.There are two types of cholesterol: Low Density Lipoproteins (LDL) and High Density Lipoproteins (HDL). LDL represents the majority of total cholesterol in the blood. It is also called "bad cholesterol" because it tends to settle in the arteries and heighten the risk of cardiovascular problems. HDL, also called "good cholesterol", aims to capture excess cholesterol in the blood, and drive it to the liver so that it is eliminated with bile.What Is The Ideal Cholesterol Level?A blood test can determine the total cholesterol level as well as the ratio between the cholesterol carried by the HDL and that carried by the LDL. The normal total cholesterol level is less than or equal to 2.0 grams per litre. In humans, the normal level of HDL-cholesterol is 0.4 to 0.65 g \/ L, in women it is 0.5 to 0.8 g \/ L.For LDL, the desirable cholesterol level is determined by the doctor based on the patient's cardiac risk and history. Nevertheless, cardiovascular risk is considered to increase when the rate exceeds 1.5-1.6 g \/ L. If the total cholesterol \/ HDL ratio is greater than 5, the relative risk of coronary heart disease is multiplied by 20. In men it should be lower than 5, in the woman lower than 4.4.Cholesterol And Cardiovascular RiskHyperlipidemia is an abnormally high level of lipids in the blood, among these lipids, cholesterol and triglycerides. This excess contributes to the hardening and thickening of the arteries of the heart. As a result, the heart has more and more difficulty adjusting to physical effort. An excessively high lipid level also increases the risk of blood clots forming, which can clog an artery and cause cardiac arrest. Cardiovascular disorders are the leading cause of death worldwide.Causes And Risk Factors Of CholesterolThe occurrence of hypercholesterolemia (excess cholesterol) depends on several factors which vary from person to person. Age, sex and genetics all have an impact. On the other hand, diet has a heavy impact on cholesterol levels. A person who consumes a lot of foods high in saturated fats and dietary cholesterol will be more prone to getting heart disease.Being overweight also promotes a bad relationship between good and bad cholesterol. Obesity lowers HDL cholesterol and increases the relative amount of LDL cholesterol. However, thin people are not free of all risks, some people's livers absorb cholesterol more slowly than others or may suffer from hereditary conditions affecting their cholesterol.Diabetes and especially type 2 diabetes also has a negative effect on the good \/ bad cholesterol ratio. Finally, smoking and stress can also increase cholesterol. In the case of stress, cortisol, a hormone, has a direct effect on the absorption of fats and sugars.