High cholesterol is a common cause of heart disease. It's important to know the basics about your cholesterol levels in order to know how to lower high cholesterol and protect your heart.

What is cholesterol?

Cholesterol is a waxy substance found in the fats in your blood. It's primarily produced in your liver. Mayo Clinic says cholesterol is necessary to keep the body going. Cholesterol helps your body to produce cells. It repairs cell membranes, manufactures vitamin D in the skin, and produces hormones too.

The dangers of high cholesterol

Having high cholesterol increases your risk of heart disease, heart attack, and stroke. Too much cholesterol may create fatty deposits in your blood vessels, making it difficult for blood to flow through your arteries. This could keep oxygen-rich blood from reaching your heart or brain, resulting in a heart attack or a stroke, according to Samaritan Health Services.

How do I know if I have high cholesterol?

There are no symptoms of high cholesterol. The only way to know if it's too high is to get a blood test from your doctor. Have your cholesterol levels checked every five years, or more frequently if your doctor recommends it. High cholesterol may be inherited, but unhealthy lifestyle choices and certain health problems can be risk factors as well. A healthy diet and exercise regimen can lower your cholesterol, but medicine is often needed too.

How can I get the most accurate cholesterol reading?

• Avoid strenuous exercise for 24 hours before the blood test.
• Do not eat or drink anything but water for 12 hours before the blood test.

What about triglycerides?

Triglycerides are the most common type of fat in the body. They are an energy source and come from food, but if your blood levels of triglycerides are too high, they can raise your risk of heart disease and stroke.

Cholesterol levels

Cholesterol levels are typically measured in milligrams per deciliter of blood (mg/dL).

• A desirable cholesterol level is below 200 mg/dL.
• 200 to 239 mg/dL is borderline.
• Over 240 mg/dL is considered high cholesterol.

Different types of cholesterol

The overall cholesterol levels shown above include a combination of three different kinds of cholesterol.

• Low-density lipoprotein. This is the so-called "bad" cholesterol. It builds up in the walls of your arteries, causing them to close and harden.
• Very-low-density lipoprotein. This cholesterol contains the most triglycerides, making the cholesterol larger, so the blood vessels are even more narrowed.
• High-density lipoprotein. This is the "good" cholesterol. It takes excess cholesterol back to your liver and helps protect against heart disease and stroke. The higher your HDL level, the better.

How to maintain a healthy cholesterol level

Genetics plays a significant role in cholesterol levels. If a parent or even a grandparent has high cholesterol, you may want to begin taking precautions even if your cholesterol levels are normal. Aside from genetics, your diet, weight, activity level, and whether or not you smoke all play a large role in the development of high cholesterol.

Unhealthy cholesterol levels may come in part from eating too much saturated fat and trans fatty acids. Limit your intake of red meat, high-fat dairy products, and fried foods. Maintain a healthy weight by exercising regularly, and if you smoke, try to quit immediately. Metabolic syndrome, obesity, type 2 diabetes, high blood pressure, polycystic ovarian syndrome, and hypothyroidism are also risk factors for high cholesterol, so if you have any of these health issues, be sure to have your cholesterol levels tested regularly.

For more on heart health and diabetes:

Diabetes and Heart Disease: What's the Risk?
Treating High Cholesterol: A Heart-Healthy Diet
10 Simple Steps for Lowering Your Triglycerides