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Total Cholesterol (Serum)

Published: August 9, 2026Updated: August 15, 2026

This test measures the total amount of cholesterol in your blood serum. Cholesterol is a type of fat that your body needs for many functions, including building healthy cells and making hormones.

Quick summary

["Your cholesterol levels help assess heart health and risk of cardiovascular disease."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 15, 2026Editorial policy

Key facts at a glance

LOINC
57932-6
Short code
CHEEZE-CHD-IgE
Synonyms
Cheddar IgE/IgE total %
Category
chemistry
Sample
serum
Container
Red top serum separator tube (SST) or gold top tube
Units
N/A
Ref low
0
Ref high
0.35
Fasting
false
Population
adult
Sex
all
Age range
≥ 1 years
Method
Immunoassay (Fluorescent Enzyme Immunoassay or Chemiluminescent Immunoassay)
CPT
86003
SNOMED
39579001
Specimen volume
1.0 mL serum (minimum 0.5 mL)
Stability
Room temperature: 8 hours; Refrigerated (2-8°C): 7 days; Frozen (-20°C or below): 1 year. Avoid repeated freeze-thaw cycles.
Hemolysis max
100
Lipemia max
100
Icterus max
50
TAT
24–72 hours
Order
routine

Why It Matters in Your Health

Cholesterol is an essential component of cell membranes and a precursor for hormones like estrogen and testosterone. However, high cholesterol levels can contribute to plaque buildup in your arteries, increasing the risk of heart disease or stroke. This test helps doctors monitor and manage your risk by providing a snapshot of your overall cholesterol status.

What to Expect During the Test

A blood sample is drawn from a vein, usually in your arm. You may feel a slight pinch when the needle is inserted, but the procedure is quick and typically painless. No special preparation is usually needed, but fasting for 9–12 hours before the test can give more accurate results for cholesterol levels.

Factors That Can Affect Results

Several factors can influence cholesterol test results, including diet (e.g., high intake of saturated fats), exercise levels, genetics, medications (like cholesterol-lowering drugs), and certain medical conditions. Stress, weight, and smoking can also play a role. If you have recent changes in your health or medications, let your healthcare provider know.

Common Questions About Cholesterol Testing

Cholesterol tests are typically performed as part of routine blood work, often included in a comprehensive metabolic panel or lipid profile. If you have symptoms like chest pain, shortness of breath, or fatigue, your doctor may recommend additional testing or monitoring.

Reference range

Negative: <0.35 kU/L; Low positive: 0.35-0.70 kU/L; Moderate positive: 0.70-3.50 kU/L; High positive: 3.50-17.50 kU/L; Very high positive: >17.50 kU/L. Results reported as IgE Ab/IgE total ratio.N/A

Specimen: serum

No special preparation required. Patient should inform the laboratory of any current antihistamine or corticosteroid use, as these medications may affect IgE levels.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Cholesterol levels are used to assess cardiovascular risk. High total cholesterol (often combined with other lipid measurements like HDL, LDL, and triglycerides) can indicate an increased risk of heart disease or stroke. Your doctor may recommend lifestyle changes, medications, or further testing if your results are outside recommended ranges.

Short name

Total Cholesterol

Frequently asked questions

How often should I get a cholesterol test?
The frequency depends on your age, risk factors, and overall health. Generally, adults without known heart disease should get tested every 4–5 years starting at age 20. If you have risk factors (e.g., high blood pressure, diabetes, or a family history of heart disease), your doctor may recommend more frequent testing.
What does a low cholesterol level mean?
Low cholesterol levels can sometimes be a concern if they are too low (hypocholesterolemia), as it may indicate an underlying condition like hypothyroidism or liver disease. However, cholesterol is also needed for normal bodily functions, so very low levels should be evaluated by a healthcare provider.
Can diet alone change my cholesterol levels?
Yes! Diet plays a major role in cholesterol management. Eating more fruits, vegetables, whole grains, and healthy fats (like those from fish and nuts) while limiting saturated and trans fats can help improve cholesterol levels naturally.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 15, 2026. · Read our editorial policy