Guide to Total Cholesterol

WRITTEN BY

The Levels Team

Updated: 05/22/2025|12 min read

Summary

Cholesterol is a waxy, fat-like substance that comes from two primary sources: about 80% is produced by the liver and other cells, while the remaining 20% comes from dietary sources like eggs, meat, and dairy products.

Why It Matters

Cholesterol helps build cell membranes, supports hormone synthesis, and assists in vitamin D synthesis. However, having too much cholesterol in your blood can be a risk factor for cardiovascular disease.

Cholesterol is transported through the bloodstream in different types of lipoprotein particles, including high-density lipoprotein (HDL), low-density lipoprotein (LDL), and triglycerides (TG). The ratio between these particles and their specific characteristics---rather than just their absolute amounts---provides crucial information about cardiovascular and metabolic health.

Your total cholesterol represents the sum of three main types of fats:

• LDL, typically the harmful type of cholesterol
• HDL, typically the beneficial type of cholesterol
• A portion of your triglycerides (specifically, 20% of your triglycerides)

LDL cholesterol is potentially dangerous because it can build up in your arteries. On the other hand, HDL cholesterol helps remove excess cholesterol from your bloodstream.

But HDL can't keep up if you have too much LDL cholesterol. Over time, plaque builds up and can narrow the arteries, reducing blood flow---a condition known as atherosclerosis. Also, plaques can suddenly rupture, causing blood clots that can block blood flow, leading to coronary artery disease, heart attacks, and stroke.

Clinical Ranges

Lab Reference Ranges:

• < 20 Years: < 170
• ≥20 Years: < 200

Lifestyle Factors That Can Impact It

Factors that can lead to healthier cholesterol:

• A plant-based diet high in soluble fiber from oats, beans, and fruits helps reduce cholesterol absorption and production
• Regular aerobic exercise can help raise HDL cholesterol, reduce triglycerides, and enhance LDL clearance from the bloodstream.
• Weight management reduces fat cells and inflammation, improves insulin sensitivity, and enhances the liver's ability to process and clear cholesterol from the bloodstream.

Factors that can raise cholesterol:

• High sugar intake drives small, dense LDL production while lowering HDL.
• Trans fats simultaneously raise LDL and lower HDL through direct effects.
• Oxidized seed oils (i.e., canola, corn, cottonseed, soybean, sunflower, safflower, grapeseed) can damage both LDL and HDL particles.
• Poor metabolic health shifts the overall cholesterol pattern toward more atherogenic forms.
• Chronic inflammation modifies cholesterol particles to become more harmful.

Other Factors That Can Impact It

Diseases

• Familial hypercholesterolemia, an inherited condition that affects how the body processes cholesterol, raises cholesterol
• Metabolic syndrome: Increases total cholesterol and LDL, decreases HDL
• Diabetes: Increases total cholesterol and triglycerides, decreases HDL
• Hypothyroidism: Increases total cholesterol and LDL
• Liver disease: Decreases total cholesterol (as the liver can't produce it normally)

Age and Gender

• Older people tend to see a rise in cholesterol levels
• Women often experience increases after menopause

Supplements

You should always consult with a doctor or healthcare professional before using a supplement.

• Red yeast rice may help lower cholesterol
• Plant sterols may help lower cholesterol
• Fish oil supplements may help lower cholesterol

Testing Accuracy and Stability

Factors That Can Affect the Accuracy of Your Test

• Not fasting for 8-12 hours before the test can artificially elevate triglycerides and total cholesterol.
• Recent illness, stress, or pregnancy can temporarily alter cholesterol levels.
• Some medications, including birth control pills and corticosteroids, may affect results.
• Time of day. It's best to get tested in the morning, around 7-9 a.m.

How it Relates to Other Markers

Total cholesterol doesn't tell you the whole story. The following ratios and tests can be more predictive of cardiovascular risk than total cholesterol alone.

• Total Cholesterol to HDL ratio
• LDL to HDL ratio
• Annual complete lipid panel
• Advanced lipoprotein testing can provide detailed information about particle sizes and numbers. It's thought that smaller cholesterol particles may be riskier. Testing may include ApoB, for example.
• Calcium scoring of coronary arteries through CT scanning might be recommended to assess the buildup of arterial plaques.
• Regular blood pressure monitoring
• Blood glucose testing
• Assessment of other cardiovascular risk factors

What Results May Mean in the Context of Other Markers

• High total cholesterol with high HDL: May indicate less risk despite elevated total.
• High total cholesterol with high triglycerides: Can suggest metabolic dysfunction requiring attention.
• Normal total cholesterol with poor ratios: Can mask risk; look at TG/HDL ratio for better insight.
• High total cholesterol with normal ApoB: May indicate less concerning larger particles.
• Normal total cholesterol with inflammation: May still indicate risk despite normal numbers.

Follow-up Considerations

Your medical provider can offer complete analysis and advice on follow-up, and the recommendations may include the following. You should always talk to your doctor if you have medical concerns or questions.

When Re-Testing May be Appropriate

• Normal results: Continue routine annual checkups
• Mildly high: If levels don't improve after 3-6 months of lifestyle changes
• Significantly high: Medical evaluation is needed for a comprehensive treatment plan, especially if:
  • Family history of heart disease
  • Other risk factors present
  • Symptoms develop
  • Multiple abnormal lipid values

Additional Testing Your Doctor May Consider

• Advanced lipoprotein testing
• Oxidized LDL
• Lp(a) if family history
• Calcium score, if indicated
• Genetic testing for familial conditions

Further Reading

The 2024 Levels Guide to understanding your cholesterol panel and blood tests

Bibliography