Cholesterol comes from two sources: about three-quarters of it is made inside your body and one-quarter is absorbed from the food you eat. In general, eating less cholesterol can help lower your cholesterol levels but genetics also play an important role in your cholesterol levels.

Risk factors for high cholesterol that you can control include:

• Diet: the more saturated fat and cholesterol you eat, the higher your blood cholesterol level will be. High saturated fat consumption is the main source of cholesterol for most people because much of it is converted to cholesterol in the liver, but eating cholesterol itself and trans fats also increase cholesterol levels.
• Obesity/Overweight: carrying extra weight tends to increase your cholesterol levels. It is also an independent risk factor for cardiovascular disease.   
• Sedentary lifestyle: lack of physical activity tends to raise LDL and lower HDL levels. Exercise has a dramatic effect on HDL, greatly increasing the levels of this “good” cholesterol. The American Heart Association recommends at least 30 minutes of physical activity on most days.

Risk factors for high cholesterol that you cannot control include:

• Age: cholesterol levels rise with age.
• Sex: women tend to have lower cholesterol levels than men before menopause. After menopause, women’s LDL cholesterol levels tend to rise to level similar to those of men.
• Heredity: since much of your blood cholesterol is made in your body, genes play a big role in how much cholesterol your body makes. High blood cholesterol tends to run in families.