Cholesterol is a fatty substance your body needs to rebuild its cells and to make certain hormones. It's carried throughout your body in your bloodstream. Your body only requires a small amount of cholesterol.
When there's too much cholesterol in your bloodstream, you have high cholesterol. This is quite a common condition. Cholesterol levels generally rise with age. High cholesterol can increase your risk of heart disease, stroke, and peripheral vascular disease.
Most of your body's cholesterol (about 80%) is made in your liver. The rest comes from your diet. Dietary cholesterol is found in foods from animal sources, such as eggs, meats, and dairy products. There are two important types of cholesterol you should know about:
- low-density lipoprotein (LDL), or "bad" cholesterol
- high-density lipoprotein (HDL), or "good" cholesterol
Most of the LDL, or "bad," cholesterol circulates in the blood and remains unused. Normally, the liver removes this "extra" cholesterol, but many people have more LDL cholesterol than the liver can handle. LDL cholesterol promotes buildup of harmful plaque (fatty deposits) in the walls of the arteries.
HDL gets its "good" name by picking up LDL cholesterol from the arteries and tissues and carrying it back to the liver, where it can be broken down.
Many factors determine whether your LDL cholesterol is high or low, including:
- age (cholesterol levels increase with age)
- alcohol consumption
- gender (men have higher cholesterol)
- level of physical activity
Another cause of high cholesterol is eating foods that are high in saturated fats and cholesterol. Other factors that can increase your cholesterol levels include an inactive lifestyle and being overweight. In some cases, high cholesterol is an inherited genetic condition, called familial hypercholesterolemia. This condition puts you at an increased chance of developing heart disease at an early age.
Some medical conditions, such as diabetes, hypothyroidism, liver disease, and kidney disease can raise cholesterol levels.