High Cholesterol: What It Can Do to You

Medically Reviewed by James Beckerman, MD, FACC on September 14, 2012
3 min read

The average American has cholesterol levels that are ‘borderline high,’ and 1 in 6 has a high level. You may wonder whether something so common can really be a serious health risk. The truth is: Absolutely.

"If you look at populations of people, the higher the cholesterol, the higher the level of heart and blood vessel disease," says Laurence Sperling, MD, head of preventive cardiology at the Emory University School of Medicine in Atlanta. It's that simple.

Your body makes cholesterol, and you also get it when you eat eggs, meats, and dairy products. When you have more than your body needs, cholesterol can cause plaque to build up in your arteries. This thick, hard plaque can clog your arteries like a blocked pipe. Reduced blood flow can lead to a stroke or heart attack.

How High Cholesterol Causes Heart Attack: If there is a clog in a coronary artery, your heart gets too little blood and oxygen. Without enough oxygen, your heart becomes weak and damaged. If the plaque breaks open, a blood clot may form on top of the buildup, further blocking blood flow. Or, a blood clot can break off and flow to an artery in another part of the body. If a clot completely blocks an artery feeding your heart, you have a heart attack.

How High Cholesterol Causes Stroke: Plaque buildup can also keep your brain from getting enough blood and oxygen. If a clot completely blocks an artery feeding your brain, you have a stroke.

A Problem Without Symptoms

Despite the risks, about 1 in 3 Americans have not had their cholesterol tested in the past 5 years. That’s how often the American Heart Association recommends screening.

Sperling says high cholesterol may not worry you enough because:

  • It doesn’t cause symptoms. So you don’t know you have it unless you get a blood cholesterol test.
  • It doesn’t cause pain. So you may be less likely to seek treatment or keep taking your cholesterol-lowering medicine.

"It's not like taking a painkiller for an aching knee, where you know it's working," he says.

Plus, the risks from high cholesterol aren’t immediate. The damage accumulates over years -- even decades. High cholesterol in your 20s and 30s can take its toll in your 50s and 60s. Because the effects take time, you may not feel the urgency to treat it. You may think you can deal with it later – but you may wait too long.

"Having high cholesterol may not hurt you today or tomorrow," Sperling says. "But if you don't do something about it, it can have a terrible cost down the road."

Protect Yourself

You can outsmart high cholesterol. Eat a healthy diet, exercise, and take medicine as your doctor recommends to lower your levels.

The first step: Ask your doctor if it’s time for you to have a fasting cholesterol blood test. If they're high, ask your doctor what numbers are ideal for you based on your personal health and risk factors. Also ask how often you need the test.

Most people should have:

  • LDL, “bad” cholesterol, less than 100 mg/dL. If you already have heart disease, you may need to aim for under 70 mg/dL.
  • HDL, “good” cholesterol, 60 mg/dL or higher
  • Triglycerides, another type of risky fat in your bloodstream, less than 150 mg/dL

Whatever you do, don't ignore your high cholesterol risks. Don't put off treatment for another year.