High Cholesterol
Information and advice on High Cholesterol, Causes and Treatments
What is High Cholesterol?
Cholesterol is a type of fat that is made by the body, in the liver. A certain amount of cholesterol is essential for good health as it is found in every cell in the body. However, many people have blood cholesterol levels that are too high. This condition is called hypercholesterolaemia and is associated with an increased risk of problems with either your heart or your circulation, including:
- Heart disease
- Stroke
- Hardening of the arteries (atherosclerosis)
- Angina
It is thought that about 70% of people aged 45 or over have a blood cholesterol level that is too high.
What are the different types of fat in the blood called?
Cholesterol, as previously mentioned, is a type of fat. Fat when in the blood is often referred to medically as a lipid. In order for cholesterol to be transported around the body, it needs to be attached to a protein. Thus, the cholestrol (lipid) combined with a protein is called a lipoprotein. Lipoproteins can be:
- High density - known as HDL (high density lipoprotein), or
- Low density - known as LDL (low density lipoprotein)
dependent upon the ratio of fat to protein.
In addition, there is another type of fat in the blood called Triglycerides. Triglycerides usually come from dietary fat. Fat which is not burned for energy is converted into triglycerides and transported in the blood to the fat cells and stored. Triglycerides are usually stored in the fatty tissue of the body, but when they are transported in the blood they are again attached to a protein, and are known as VLDL (very low density lipoproteins).
A raised level of VLDL is a risk factor, when combined with a high LDL cholesterol level, in the development of heart disease. This risk is increased in people who in addition have diabetes.
A person who has high VLDL cholesterol (i.e. a high level of triglycerides in their blood) has the condition hypertriglyceridaemia (or hypertriglyceridemia - American spelling).
LDL (Low Density Lipoprotein) - Bad Cholesterol
Most blood cholesterol is in the form of LDL, which is comprised mainly of fat, with a smaller amount of protein. A high level of LDL cholesterol is a major risk factor in the development of cardiovascular disease. This is because too much LDL in the blood can cause cholesterol deposits to be laid down in the arteries, causing plaques which narrow them.. Think of a "furred up pipe" in a hard water area where limescale is laid down inside a water pipe, narrowing the diameter of the pipe. A similar process happens with LDL cholesterol inside your arteries.
A person who has high LDL cholesterol has the condition dyslipidaemia (or dyslipidemia - American spelling).
HDL (High Density Lipoprotein) - Good Cholesterol
A smaller amount of cholesterol is transported in the blood as HDL cholesterol. This is made up mostly of protein, with a smaller amount of fat. HLD cholesterol is known as "good cholesterol" because it helps to prevent cholesterol deposits being laid down in the arteries.
Total Cholesterol (TC) versus the Total Cholesterol / HDL Cholesterol Ratio (TC:HDL)
A high total cholesterol level is a risk factor for cardiovascular disease and associated problems. However, doctors consider the ratio of total cholesterol to HDL cholesterol to be another indicator. Sometimes referred to as TC:HDL ratio, a lower value is to be preferred - in other words - a higher value for HDL cholesterol and a lower value for LDL cholesterol.
A person who has high total cholesterol has the condition hypercholesterolaemia (or hypercholesterolemia - American spelling).
© Medex UK 2009. All rights reserved. Trademarks remain the property of their respective owners. Please note that this site is for information only, we do not provide nor do we fulfill any prescriptions.