What Is Cholesterol?

What is cholesterol?

Cholesterol is a waxy, fat-like substance (lipid) that does many essential jobs in your body. It’s vital for you to live. But too much can be harmful. It may raise your risk for heart and blood vessel problems.

There’s cholesterol in all your body’s cells. But you’re probably most familiar with it as something that travels in your blood. When your healthcare provider does a test called a lipid panel, they measure how much cholesterol is in your blood. This test can help them offer treatment to protect your heart.

What are the different types of cholesterol?

You might see these types of cholesterol listed on your lipid panel results:

• HDL cholesterol is a “good” cholesterol that experts believe can help protect your arteries.
• LDL cholesterol is a “bad” cholesterol that can make a sticky substance called plaque build up in your arteries.
• VLDL cholesterol is another “bad” cholesterol that can also make plaque build up.
• Non-HDL cholesterol refers to all the cholesterol in your blood except for HDL.

Non-HDL cholesterol includes LDL and VLDL. It also includes cholesterol carried on intermediate-density lipoproteins (IDLs) and chylomicrons. These last two usually aren’t listed separately.

What does cholesterol do?

Cholesterol has many important functions in your body. These include:

• Giving structure to the protective cover around each cell (cell membrane) and guarding what can enter or leave the cell
• Helping your liver make a liquid (bile) that breaks down food after you eat
• Serving as a building block for certain hormones (including sex hormones) and vitamin D

Where does cholesterol come from?

Your liver makes enough cholesterol to support your body’s needs. In fact, it makes about 80% of all the cholesterol in your body. The rest comes from the foods you eat. The biggest sources are foods high in saturated fat (like whole-fat dairy and red meat) or trans fat (like packaged desserts and fried foods).

Usually, your body can filter out the cholesterol it doesn’t need. But many factors can affect how much cholesterol stays in your body. These include things like your age and the genes you’re born with.

Where is it located?

Cholesterol is in every cell in your body. It also travels through your blood — but it can’t do this by itself because of the way it’s made. Cholesterol molecules need to be attached to other molecules. So, cholesterol teams up with proteins and another type of lipid called triglycerides. These molecules bind together to form a particle called a lipoprotein.

Lipoproteins transport cholesterol in your body. They’re like little boats that travel through your bloodstream. They deliver cholesterol to your body’s tissues to help them work properly.

Some lipoproteins pick up extra cholesterol and carry it to your liver. Your liver then breaks down the cholesterol and gets rid of it. This process is called reverse cholesterol transport. It helps support healthy cholesterol levels in your blood.

What conditions are related to cholesterol?

Your healthcare provider will measure your cholesterol levels and tell you if they’re in the healthy range. Conditions related to unhealthy cholesterol levels include:

• High cholesterol (hyperlipidemia): This means your total cholesterol is higher than 200 mg/dL.
• High LDL cholesterol (hypercholesterolemia): This is when your LDL cholesterol is too high. This usually means over 100 mg/dL, but it can vary by person. High LDL cholesterol that runs in families is called familial hypercholesterolemia.
• Metabolic syndrome: Low HDL cholesterol is a sign of this condition.

High cholesterol can cause a wide range of health problems. For example, it can contribute to plaque buildup in your arteries. This can lead to conditions like coronary artery disease or carotid artery disease. You won’t have symptoms of high cholesterol until these complications develop.

We often think of high cholesterol as something that affects adults. But it’s important to know that it can also affect kids. There are often genetic causes for high cholesterol in children.

What factors affect my cholesterol levels?

Many things can affect your cholesterol levels. These include:

• Age: As you get older, your cholesterol levels rise.
• Foods you eat: Saturated fat and trans fat in foods raise your LDL (“bad”) cholesterol.
• Exercise: Regular exercise can raise your HDL (“good”) cholesterol. 
• Your genes: The genes you’re born with partly control how much cholesterol your body makes. High blood cholesterol can run in biological families.
• Your sex: Before menopause, females usually have lower total cholesterol levels than males. But after menopause, their LDL levels tend to rise and their HDL can drop.

When should I see a healthcare provider?

See a provider for an annual physical. Your provider will tell you how often you need to have your cholesterol levels checked. It depends on your age and your risk factors for heart disease.

You might need treatment to support healthy cholesterol levels. If so, you may need more frequent cholesterol checks. These help your provider keep an eye on how well the treatment is working. Your provider will tell you when to come back for these visits.

How can I improve my cholesterol?

You can help support healthy blood cholesterol levels by:

• Limiting foods high in saturated fat
• Avoiding foods that contain trans fat
• Upping your intake of foods that contain soluble fiber and omega-3 fatty acids
• Using plant-based fats (like extra virgin olive oil) instead of animal-based fats (like butter)
• Exercising for at least 30 minutes, five to seven times per week