Cholesterol travels through your blood attached to a protein. This cholesterol-protein package 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 mostly fat with only a small amount of protein. LDL is the bad kind of cholesterol because it can clog your arteries. If you have high cholesterol, your doctor will want you to lower your LDL.
High-density lipoproteins (HDL) help clear the bad cholesterol from your blood and keep it from clogging your arteries. HDL is the good kind of cholesterol. High levels of HDL (60 or above) can protect you from a heart attack.
Triglycerides are another type of fat in your blood. If you have high triglycerides and high LDL, your chances of having a heart attack are higher.
High cholesterol may run in your family. The foods you eat also may cause high cholesterol.
Causes include:
- Your diet. Eating too much saturated fat and cholesterol can cause high cholesterol. Saturated fat and cholesterol come from animal foods such as beef, pork, milk, eggs, butter, cheese
- Your weight. Being overweight may raise triglycerides and lower HDL.
- Your activity level. Not exercising may raise LDL and lower HDL.
- Your overall health. Having diseases such as low thyroid can raise cholesterol. Cigarette smoking may lower HDL.
- Your age. After you reach age 20, your cholesterol starts to rise. In men, cholesterol levels usually level off after age 50. In women, cholesterol levels stay fairly low until menopause. After that, they rise to about the same level as in men.
- Your family. A disease called a lipid disorder can also cause high cholesterol. This rare problem is inherited from family members, and it changes how your body handles cholesterol.
There are usually no signs or symptoms of high blood cholesterol. Many people don’t know that their cholesterol level is too high. If cholesterol builds up in your arteries, it can block blood flow to your heart or brain and cause a heart attack or stroke.
Everyone age 20 and older should have their cholesterol levels checked at least once every 5 years. You and your doctor can discuss how often you should be tested.