Cholesterol is a form of fat we need. It helps make the outer membranes of our bodies' cells stable. But for decades, doctors have known that people with high total cholesterol levels are more likely to get heart disease. They’ve also found that the different forms of cholesterol ("good" and "bad") play a role. High total cholesterol, high bad cholesterol, or low good cholesterol could raise your chances.
For example, low-density lipoprotein (LDL), or "bad" cholesterol, can stick to blood vessel walls. Over time, it can play a role in clogging arteries in a process called atherosclerosis. Narrowed arteries in your heart can then develop sudden blood clots, causing heart attacks.
Triglycerides are another fat that doctors measure with cholesterol testing. High levels can raise your chances of having a heart attack or stroke . This is especially true when you have low levels of “good” cholesterol, called high-density lipoprotein (HDL). High triglyceride levels also make you more likely to develop diabetes.
Cholesterol Tests: The Good, the Bad, and the Fatty
The different kinds of cholesterol and other fats in your blood are together called lipids. Doctors measure and diagnose lipid problems with a simple blood test. You'll probably have to fast for 9 to 12 hours before it to make sure it's not affected by any food you recently ate.
A lipid profile usually gives results for four different types:
- Total cholesterol
- LDL (low-density lipoprotein), the "bad cholesterol"
- HDL (high-density lipoprotein), the "good cholesterol"
- Triglycerides, the most common type of fat in your body
Some lipid panels can give even more detailed information, like the presence and sizes of various fat particles in your blood. Researchers are looking into what, if any, effect these traits have on heart disease. There's no clear guidelines on when this more advanced testing is needed.
Your Cholesterol Test Results
So you've gone hungry overnight, endured a small bloodletting, and dutifully returned to get your results. Now, what do the numbers mean?
For total cholesterol:
- 200 milligrams per deciliter (mg/dL) or less is normal.
- 201 to 240 mg/dL is borderline.
- More than 240 mg/dL is high.
For HDL ("good cholesterol"), more is better:
- 60 mg/dL or higher is good -- it protects against heart disease.
- 40 to 59 mg/dL is OK.
- Less than 40 mg/dL is low, raising your chance of heart disease.
For LDL ("bad cholesterol"), lower is better:
- Less than 100 mg/dL is ideal.
- 100 to 129 mg/dL can be good, depending on your health.
- 130 to 159 mg/dL is borderline high.
- 160 to 189 mg/dL is high.
- 190 mg/dL or more is very high.
For triglycerides, lower is better:
Your doctor will consider your overall likelihood of heart disease to set your personal LDL goal. For people who are at higher risk of heart disease or who already have it, your LDL should be less than 100 mg/dL. (Your heart doctor might recommend an even lower LDL -- less than 70 mg/dL -- if your risk of heart disease is very high.)
If you have a moderately high chance of heart disease, an LDL less than 130 mg/dL is your target. If your risk of heart problems is fairly low, less than 160 mg/dL is probably fine.
What You Can Do About Abnormal Lipid Levels
Lifestyle changes are the first thing to tackle to reduce your chance of heart disease. Your doctor may also recommend that you start taking prescription drugs to help your cholesterol level.
Lifestyle habits to lower cholesterol
A cholesterol-lowering diet can bring down bad cholesterol by up to 30%. A diet low in saturated fat and simple carbohydrates and that has no more than 200 mg of cholesterol daily can lower LDL cholesterol. Fiber and plant sterols (found in special margarines and other foods) help, too.
Keep these dietary tips in mind:
- Cut saturated fat to less than 7% of your total calories.
- Avoid trans fat completely. Check the ingredients label for “partially hydrogenated” oils. Those are trans fats. Even if a product says "0 grams trans fat," it can have a small amount of trans fat (less than half a gram per serving), and that adds up.
- Read food labels. Products that say “low cholesterol” or “no cholesterol” could be too high in saturated fats or sugar.
Regular aerobic exercise can lower bad cholesterol (LDL) and raise good cholesterol (HDL). If you smoke, quit.
Lifestyle changes such as diet, exercise, and weight loss are also effective ways to improve your triglyceride levels. Ask your doctor for a sensible diet that will help. If you smoke, get suggestions on ways to help you quit.
Medications and procedures
If lifestyle changes don't lower cholesterol levels enough, you can try medications or a combination of treatments. If you stick with your new healthy habits, however, you may be able to work with your doctor to reduce the amount of medicine you take or stop it altogether.
Your doctor may prescribe:
Statins. These are the most effective and commonly used cholesterol drugs. They block your liver’s ability to make cholesterol. They usually don’t cause problems, but in rare instances, they can damage the liver and muscle. Because of this, your doctor will do blood tests to check your liver function after you start treatment and if there are any signs of problems. There have also been reports of memory loss and a small increased risk of type 2 diabetes. The benefits may outweigh the risks, so talk with your doctor about them.
Statins available in the U.S. are:
- Atorvastatin (Lipitor)
- Fluvastatin (Lescol)
- Lovastatin (altoprev, Mevacor)
- Pitavastatin (Livalo)
- Pravastatin (Flolipid, Pravachol)
- Rosuvastatin calcium (Crestor)
- Simvastatin (Zocor)
Niacin . Doctors may prescribe this to help raise HDL ("good") cholesterol. To be effective, it must be taken in large doses. In these amounts, it often causes skin flushing and an upset stomach. Newer versions of niacin made to minimize these side effects may be easier to take. Despite its effects on cholesterol levels, an important scientific study recently found that adding niacin to statin therapy did not lower the risk of heart problems.
Ezetimibe (Zetia). This drug limits the amount of cholesterol the small intestine can absorb. People who take it also usually take a statin, which can reduce cholesterol another 25%. Zetia is controversial, however, because of less evidence that it lowers the risk of heart attack or death from heart disease.
Bile acid sequestrants. Also known as cholestyramine and colestipol, these may lower total and LDL cholesterol in some people. Side effects include bloating, gas, and constipation. If your cholesterol level can't be controlled by using medication, your doctor may try to combine a bile acid sequestrant and a statin.
Proprotein convertase substilisin kexin type 9 (PCSK9) inhibitors. This is a newer class of cholesterol-lowering drugs that’s used in patients with in heterozygous familial hypercholesterolemia who cannot control their cholesterol through diet and statin treatments. It’s also used in those with clinical atherosclerotic heart disease. The drugs alirocumab (Praluent) or evolocumab (Repatha) block the liver protein PCSK9, which hinders the liver’s ability to remove LDL-cholesterol from the blood. This reduces the amount of bad cholesterol in the bloodstream. Evolocumab in particular, has proven to be effective in lowering the risk of heart attack and strokes in people who have cardiovascular disease.
Triglyceride medications. Your doctor may also prescribe medicine if your triglyceride number is above 500 mg/dL. You may need to take these meds for a long time to keep your triglyceride levels out of the danger zone.
LDL apheresis. This isn't a drug. It's a blood-cleansing procedure that may help with severe genetic cholesterol disorders. Over several hours, blood is removed from the body, chemically cleansed of LDL cholesterol, and then returned to the body. Treatments every 2 to 3 weeks can cut average LDL cholesterol by 50% to 80%, but they’re costly in both time and money.
Other Risks and Follow-up Testing
Your cholesterol numbers don't determine your destiny. Remember, other things besides cholesterol can also lead to heart disease. Diabetes, smoking, high blood pressure, obesity, exercise, and genetics are important as well.
People with normal cholesterol can have heart disease; people with high cholesterol can have healthy hearts. Overall, though, more people whose cholesterol levels are off will get heart disease.
Experts recommend follow-up cholesterol testing every 5 years for most people. If your lipid results aren't what you and your doctor had hoped for, or if you have other reasons to be concerned about heart disease, you'll need cholesterol tests more often.