Cholesterol is a type of fat called a lipid, which the body uses in a variety of ways. Your liver manufactures cholesterol, and you also get it from the foods you eat.
Although the body needs some cholesterol, overly high levels cause it to build up in the arteries. This process leads to hardening of the arteries, or atherosclerosis.
Cholesterol travels through the blood attached to a protein. This package of cholesterol (a lipid) and protein is called a lipoprotein. Lipoproteins are either high-density or low-density, based on how much protein and fat they have.
- Low-density lipoproteins (LDL) are the “bad” cholesterol. LDL is mostly fat with only a small amount of protein. It can clog your arteries. If you have high cholesterol, your doctor will want you to lower your LDL.
- High-density lipoproteins (HDL) are the “good” cholesterol. HDL is more protein than fat. It helps clear the bad cholesterol from your blood so it does not clog your arteries. A high level of HDL can protect you from a heart attack.
- Triglycerides are another type of fat in the blood that can affect your health. If you have high triglycerides and high LDL, your chances of having a heart attack are higher.
- Diet: Consuming too much saturated fat, trans fat, and cholesterol can raise your cholesterol. These substances are commonly found in animal products (such as meats, whole milk, egg yolks, butter, and cheese), many packaged foods, and snack foods like cookies and chips.
- Weight: Being overweight may raise triglycerides and lower “good” HDL.
- Exercise: Not getting enough exercise may raise LDL and lower HDL.
- Age: Cholesterol starts to rise after age 20. In men, it usually levels off after age 50. In women, it stays fairly low until menopause. After that, cholesterol levels rise to about the same levels as in men.
- Family history
Cholesterol levels can be measured with a single blood test.