Total cholesterol

Definition

Total cholesterol is a blood test to measure all types of cholesterol in your blood. Cholesterol is a fatty, wax-like substance found in all parts of the body.

The cholesterol test is often done as part of a lipid profile, which measures the fats (lipids) in your blood:

• Total cholesterol
• Low-density lipoprotein cholesterol (LDL cholesterol)
• High-density lipoprotein cholesterol (HDL cholesterol)
• Triglycerides (another type of fat in your blood)
• Very low-density lipoprotein cholesterol (VLDL cholesterol)

Alternative Names

Serum cholesterol; Lipid panel - total cholesterol; Lipid profile - total cholesterol

How the Test is Performed

A blood sample is needed. Most of the time, blood is drawn from a vein located on the inside of the elbow or the back of the hand.

How to Prepare for the Test

You should not eat for 9 to 12 hours before the test.

Alcohol and some medicines can interfere with blood test results.

• Make sure your health care provider knows what medicines you take, including over-the-counter medicines and supplements.
• Your provider will tell you if you need to stop taking any medicines before you have this test.
• Do not stop or change your medicines without talking to your provider first.

How the Test will Feel

You may feel slight pain or a sting when the needle is inserted. You may also feel some throbbing at the site after the blood is drawn.

Why the Test is Performed

Total cholesterol is usually measured together with other blood fats as part of a lipid profile. It is done to help determine your risk of developing heart disease.

A high total cholesterol level may lead to atherosclerosis. This increases your risk for heart attack and stroke.

Normal Results

Results may indicate:

• Optimal: Less than 200 mg/dL (5.18 mmol/L)
• Borderline high: 200 to 239 mg/dL (5.18 to 6.19 mmol/L)
• High: More than or equal to 240 mg/dL (6.22 mmol/L)

Normal value ranges may vary slightly among different laboratories. Talk to your provider about the meaning of your specific test results.

What Abnormal Results Mean

A high total cholesterol level may be due to:

• Eating a diet high in saturated fats
• Lack of physical activity
• Stress
• Drinking too much alcohol
• Being overweight or having obesity
• Diabetes
• Metabolic syndrome
• Disorder passed down through families in which there are high amounts of cholesterol and triglycerides in the blood (familial combined hyperlipidemia)
• Side effect of certain medicines
• Underactive thyroid (hypothyroidism)
• Kidney or liver disease

If your total cholesterol is high, your provider may recommend changes in your lifestyle such as:

• Eating a healthy diet
• Losing weight (if you are overweight or have obesity)
• Getting regular exercise
• Quitting smoking
• Avoiding alcohol

You may also need medicine to lower your cholesterol level if you have diabetes or are at risk of heart disease. While taking medicines to lower your cholesterol level, you should continue the lifestyle changes.

A low total cholesterol level is usually considered desirable. But, it may be due to serious medical conditions too, in which case it is undesirable:

• Rare genetic disorder that runs in families
• Overactive thyroid (hyperthyroidism)
• Severe liver disease
• Malabsorption syndrome (conditions in which the small intestine does not absorb fats well)
• Malnutrition
• Cancer

Risks

There is little risk involved with having your blood taken. Veins and arteries vary in size from one person to another and from one side of the body to the other. Taking blood from some people may be more difficult than from others.

Other risks associated with having blood drawn are slight, but may include:

• Fainting or feeling lightheaded
• Multiple punctures to locate veins
• Hematoma (blood buildup under the skin)
• Excessive bleeding
• Infection (a slight risk any time the skin is broken)

Considerations

Certain medicines, pregnancy, infection, and some medical conditions can affect test results.

References

Bredefeld CL, Lau R, Hussain MM. Lipids and dyslipoproteinemia. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 24th ed. Philadelphia, PA: Elsevier; 2022:chap 18.

Genest J, Mora S, Libby P. Lipoprotein disorders and cardiovascular disease. In: Libby P, Bonow RO, Mann DL, Tomaselli, GF, Bhatt DL, Solomon SD, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 12th ed. Philadelphia, PA: Elsevier; 2022:chap 27.

Grundy SM, Stone NJ, Bailey AL, et al. 2018 AHA/ACC/AACVPR/AAPA/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA Guideline on the management of blood cholesterol: executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Circulation. 2019;139(25):e1046-e1081. PMID: 30565953 pubmed.ncbi.nlm.nih.gov/30565953/.

Mora S, Libby P, Ridker PM. Primary prevention of cardiovascular disease. In: Libby P, Bonow RO, Mann DL, Tomaselli, GF, Bhatt DL, Solomon SD, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 12th ed. Philadelphia, PA: Elsevier; 2022:chap 25.

Robinson JG. Disorders of lipid metabolism. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 190.