It is produced in the liver and some is also obtained from the diet. It is a constituent of cells, e.g. brain cells. The lipoproteins also contain other types of fat. The level of cholesterol in the blood depends partly on genetic factors but diet is also important. The three most important factors are smoking, high blood pressure and high blood cholesterol .
Obesity is also an important factor.
Other risk factors are related to behaviour and lifestyle and they can be changed. They include smoking, obesity, type II diabetes , a poor diet, excess alcohol consumption and lack of physical activity. A good control of these risk factors is particularly important for those people who have non-modifiable risk factors, such as a family history of heart disease. The risk factors interact with each other and their effect is cumulative. Obese people tend to have increased levels of blood cholesterol, high blood pressure and an increased risk of diabetes.