"We need some cholesterol, there's no question about it, but not too much," says Northwestern Medicine Preventive Cardiologist Donald M. Lloyd-Jones, MD. "It's when we're exposed to excess levels of bad cholesterol that we get into trouble."

There are two types of cholesterol-carrying particles in the blood. The high-density lipoprotein (HDL) type is known as a good cholesterol-carrying particle, while the low-density lipoprotein (LDL) type is known as a bad cholesterol-carrying particle. The cholesterol in these particles is the same, but the purpose of the particles is different. When there are too many bad cholesterol particles in your blood, cholesterol can start to build up as plaque in the walls of your arteries. This can cause many health issues, including high blood pressure, coronary heart disease, heart attack and stroke. Your liver is supposed to clear these excess LDL particles from your bloodstream, but if you have too many of them from eating a diet high in fat or from your genetic makeup, your liver can't keep up, resulting in excess bad cholesterol in your bloodstream.

Familial Hypercholesterolemia

People with familial hypercholesterolemia (FH) have a genetic mutation that causes problems with the receptors in the liver that clear LDL cholesterol. These people are limited in their ability to get rid of LDL cholesterol. Roughly 1 in 250 people have FH, which means their body can't clear LDL cholesterol particles, so they remain in their bloodstream and build into plaques that can narrow and obstruct their arteries.

Severe FH can result in heart attacks or coronary heart disease as early as age 20. While lumpy cholesterol deposits in certain tissues like the Achilles tendon are a symptom of FH, people with FH can be completely asymptomatic until it's too late.

Early Screening Means Early Intervention

"Screening is so important," says Dr. Lloyd-Jones. "If your child has a family history of FH because any of their first-or second-degree relatives have it, they should be screened as early as ages 3 to 5. All children should be screened at ages 9 to 11. And at the very latest, everyone should be screened for high cholesterol by age 21."

Screening, in the form of a quick blood test, allows for early intervention. And intervention can often be simple but effective. Medications called statins increase the activity of the receptors in the liver that clear LDL cholesterol particles. Typically, people with high cholesterol can take one pill a day to help keep their cholesterol at a healthy level. There are many different types of statins that your physician can prescribe to you based on your personal health history. There are also newer medications called PCSK9 inhibitors that are administered via simple, tiny injections every two weeks that can decrease LDL levels by up to about 70%.

In rare cases of FH, the cholesterol receptors in the liver don't work at all, even with medication. In these cases, a treatment called LDL apheresis can help. During this treatment blood is removed from the body, cleaned up to get rid of all the LDL particles and then returned to the body.

If plaque does build up in the walls of your arteries, it won't go away. However, medications like statins and PCSK9 inhibitors can change the biology of the plaque, reducing its ability to cause heart attack, heart disease and stroke. These medications take away the fuel for the plaque and allow it to scar down instead of growing and becoming more inflamed, which narrows arteries and obstructs blood flow.

Lifestyle Is Important

Everyone has a different ability to absorb cholesterol. Even without FH, some people are fairly resistant to absorbing cholesterol, and up to about 25% of people are "hyperabsorbers" for cholesterol, according to Dr. Lloyd-Jones. This means that cholesterol and saturated fat in their diet gets into their blood as bad cholesterol more easily.

"For everyone, lifestyle is an incredibly important way to keep cholesterol levels in check," says Dr. Lloyd-Jones. "It's important to be aware of your fat and cholesterol intake, be a careful label reader, and maintain a healthy diet with leaner proteins and plenty of fruits and vegetables."

Eating healthy, eating a predominately plant-based diet and staying away from fatty foods like red meats can make a huge difference and lead to successful outcomes in people with high cholesterol.

As far as the age-old debate about the healthiness of eggs goes, Dr. Lloyd-Jones says, "If you have high cholesterol, egg yolks are not a good idea, but egg whites have high-quality protein content."