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Total Cholesterol in Serum

Published: August 9, 2026Updated: August 16, 2026

This test measures the total amount of cholesterol in your blood serum, a key indicator of heart health and lipid metabolism.

Quick summary

["Cholesterol levels help assess your risk for cardiovascular disease."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
29766-3
Short code
Trigl Fld-sCnc
Synonyms
Trigl Fld-sCnc
Category
glucose
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
true
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why Is This Test Done?

Your healthcare provider may order this test to evaluate your risk of heart disease, monitor existing conditions like high cholesterol, or check for metabolic disorders. It’s often part of routine check-ups or when symptoms like fatigue, chest pain, or unexplained weight changes are present.

What to Expect Before the Test

No special preparation is needed, but you may be asked to fast for 8–12 hours before the test if it’s part of a lipid panel. Bring any medications you’re currently taking, as some (like cholesterol-lowering drugs) can affect results.

How the Test Works

A blood sample is drawn from a vein, usually in your arm. The serum (liquid part of blood after clotting) is then analyzed to measure cholesterol levels using automated laboratory techniques.

What the Results Mean

Results are typically reported in milligrams per deciliter (mg/dL). While specific ranges vary by lab, higher-than-normal levels may signal increased cardiovascular risk, prompting lifestyle or medical interventions.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

This test is crucial for identifying elevated cholesterol, which can contribute to plaque buildup in arteries. High levels may increase the risk of heart attack, stroke, or peripheral artery disease, especially when combined with other risk factors like smoking, diabetes, or high blood pressure. Regular monitoring helps manage these risks through diet, exercise, and medications if needed.

Short name

Total Cholesterol

Frequently asked questions

What causes high cholesterol levels?
High cholesterol can result from genetics, an unhealthy diet (high in saturated or trans fats), lack of physical activity, obesity, or certain medical conditions like diabetes or hypothyroidism. Lifestyle changes or medications may help manage it.
How can I lower my cholesterol naturally?
Focus on a heart-healthy diet rich in fruits, vegetables, whole grains, and lean proteins. Avoid trans fats and limit saturated fats. Exercise regularly (aim for at least 150 minutes of moderate activity weekly), maintain a healthy weight, and avoid smoking.
Will fasting affect my cholesterol test results?
Yes, fasting for 8–12 hours before the test can give more accurate results, as cholesterol levels fluctuate with food. Follow your healthcare provider’s instructions to ensure reliable outcomes.
  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 16, 2026. · Read our editorial policy