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Total Cholesterol (Serum)

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

This test measures the total amount of cholesterol in your blood serum. Cholesterol is a type of fat that your body needs for healthy cell function but also plays a role in heart health.

Quick summary

["Your blood cholesterol levels help assess your risk for heart disease and other health conditions."]

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

Key facts at a glance

LOINC
39551-7
Short code
Cow Dander IgE/IgE total %
Synonyms
Cow Dander IgE/IgE total %
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
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 This Test Is Done

Doctors may order a total cholesterol test to check for high cholesterol, which can increase the risk of heart disease, stroke, or other health problems. It’s often part of routine check-ups or when you have risk factors like high blood pressure, diabetes, or a family history of heart disease.

What to Expect Before the Test

You’ll typically have a small needle inserted into your arm to draw blood. The process takes a few minutes. Avoid eating or drinking anything for 12 hours before the test, as fasting can affect results.

What the Results Mean

Results are usually reported as a single number (total cholesterol level). While specific ranges vary by lab, higher levels may signal a need for lifestyle changes or medical advice to manage cholesterol.

Common Causes of Abnormal Results

High cholesterol can result from diet, genetics, obesity, or lack of physical activity. Low levels may occur due to certain medications, liver disease, or malnutrition.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Total Cholesterol

Frequently asked questions

What causes high cholesterol levels?
High cholesterol can be influenced by diet (e.g., high intake of saturated fats), genetics, obesity, lack of exercise, or certain medical conditions like diabetes.
How long does it take to get results?
Results are usually available within 1–3 business days, depending on your lab and insurance. Follow-up with your doctor if you have questions about your results.
Can I eat before the test?
Yes, but fasting is recommended for most cholesterol tests. Ask your doctor or lab about specific instructions for your test.
  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