Two things can cause high cholesterol: Your diet and your family history.
Diet: Saturated fat raises cholesterol levels. The more saturated fat you consume, the higher your cholesterol will rise. Foods high in saturated fat include full-fat dairy products (such as butter and cream), and fatty meats. Processed foods that contain a lot of trans fats (man-made fats made with hydrogenated vegetable oil) are known to raise levels of "bad" LDL cholesterol.
Family history: What you can't prevent is high cholesterol that runs in your family. This is called familial hypercholesterolemia. This condition causes severe elevations in total cholesterol and "bad" LDL cholesterol, which can lead to heart attacks at an early age.
Age and sex are also factors that influence cholesterol. Younger women tend to have lower LDL levels than their male counterparts. After menopause, however, women can have higher LDL levels than men. Men generally tend to have lower HDL levels than women.
Additional risk factors for elevated cholesterol include:
- Smoking. This can damage your blood vessels, which makes it easier for cholesterol to stick to them. Smoking may also lower your HDL levels.
- Overweight. Carrying extra pounds increases your chances of having high cholesterol.
- Drinking too much. Alcohol can affect your cholesterol levels. If you don't drink, don't start. If you do, keep it to levels recommended by your physician.
- A sedentary life. Exercise can raise your HDL and lower your LDL levels. Not exercising can do the exact opposite.
- High blood pressure. As with smoking, high blood pressure can damage your artery walls, making it easier for fatty deposits to stick to them.
- Diabetes. High blood sugar contributes to higher LDL and lower HDL levels. High blood sugar also damages the lining of your arteries.
- Family history. Even if you don't have familial hypercholesterolemia, you are at greater-than-normal risk of heart disease if you have high cholesterol and a close family member with heart disease.