High cholesterol levels are asymptomatic, and in many cases the first sign of any problem is a serious health issue. To help reduce the risk of this occurring, cholesterol levels are measured by a simple blood test. Your healthcare professional can organise this for you, along with other measurements of your cardiovascular health, such as blood pressure testing.
Cholesterol is transported through the blood stream in particles known as lipoproteins . The two most important varieties of lipoproteins to be aware of are low-density lipoproteins (LDL) and high-density lipoproteins (HDL).
High levels of LDL-cholesterol can lead to fatty deposits in the artery walls referred to as atherosclerosis, or "hardening of the arteries". Atherosclerosis makes the blood vessels narrower and stiffer, and consequently increases the risk of heart disease and stroke. This form of cholesterol is sometimes referred to as "bad" cholesterol.
High-density lipoproteins (HDL-cholesterol) help to reduce the risk of heart disease as they have the ability to help remove excess cholesterol from the arteries and other parts of the body. For this reason they are sometimes referred to as "good" cholesterol.
The narrowing of the arteries associated with high cholesterol levels can sometimes cause symptoms of chest pain (angina) or leg pain intermittent claudication, especially with exercise.
High production of cholesterol by the liver may contribute to the development of gallstones, symptoms of which include episodic abdominal and back pain, especially after consumption of fatty foods.
Cholesterol levels in the blood depend on both dietary factors and the amount of cholesterol manufactured by the body. High consumption of saturated fat, trans fat and cholesterol in foods may make your total cholesterol and LDL cholesterol levels rise.
Genetics also play a role in some people with high cholesterol. Your genes will partly determine how much cholesterol you naturally produce. Familial hypercholesterolaemia is more likely to be present in people who experience a heart attack at an early age or who have a family member who had a heart attack at an early age.
Being overweight contributes to increased LDL-cholesterol.
Other blood markers that may be associated with high cholesterol levels and are also risk factors for cardiovascular disease include high levels of a compound called homocysteine and high blood levels of triglycerides (fats).
Free radical damage to cholesterol molecules is believed to increase their ability to damage blood vessels.